Smart Materials
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
computer science crazy
Super Moderator
******

Posts: 3,048
Joined: Dec 2008
#1
21-02-2009, 10:42 PM


They are the materials which have the capability to respond to changes in their condition or the environment to which they are exposed, in a useful and usually repetitive manner. They are called by other names such as,

· Intelligent materials,

· Active materials and

· Adoptive materials.

The devises that are made using smart materials are called Smart Devices. Similarly the systems and structures that have incorporated smart materials are called Smart Systems and Smart Structures. In other words the complexity increases from smart materials to smart structures.

Stimulus Response System
[img]2.bp.blogspot_7UH1P0Umjhk/STZ3zpwnngI/AAAAAAAABUk/FBZYKp3bq9Q/s320/Smart_Materials.jpg[/img]
[img]2.bp.blogspot_7UH1P0Umjhk/STZ36VXgwxI/AAAAAAAABUs/CjvkFd6nZ_0/s320/Smart+Materials.gif[/img]
A smart material or an active material gives an unique output for a well defined input. The input may be in the form of mechanical stress / strain, electrical / magnetic field or changes in temperature. Based on input and output, the smart materials are classified as follows.

1. Shape Memory Alloys (SMAs)

They are the smart materials which have the ability to return to some previously defined shape or size when subjected to appropriate thermal changes.

Eg.: Titanium-Nickel Alloys.

2. Magnetostrictive Materials

They are the smart materials which have the ability to undergo deformation when subjected to magnetic field.

Eg.: Terfenol-D, (Alloy of Iron and Terbium)

3. Piezoelectric Materials

These are the materials which have capability to produce a voltage when surface strain is introduced. Conversely, the material undergo deformation (stress) when an electric field is applied across it.

4. Electrorheological Fluids
They are the colloidal suspensions that undergo changes in viscosity when subjected to an electric field. Such fluids are highly sensitive and respond instantaneously to any change in the applied electric field.

Applications

1. Smart materials are used in aircrafts and spacecrafts to control vibrations and excessive deflections.

2. Smart concrete is used in smart structures. Smart concrete (a composite of carbon fibres and concrete) is capable of sensing minute structural cracks / flaws.

3. Smart materials have good potential to be used in health care markets. Active control drug delivery devices such as Insulin Pump is a possibility.
Smart materials have applications in the design of smart buildings and state of art vehicles. Smart materials are used for vibration control, noise mitigation, safety and performance.
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
Reply
project topics
Active In SP
**

Posts: 2,492
Joined: Mar 2010
#2
12-04-2010, 11:45 AM


.docx   APPICATION OF SMART MATERIALS IN MODERN ENGINEERING FIELDS.docx (Size: 26.68 KB / Downloads: 539)

APPICATION OF SMART MATERIALS IN MODERN ENGINEERING FIELDS
Structural Applications of Smart Materials in Construction Engineering Using Robotics
Abstract “
Sensors and Actuators designs have mimicked nature to a large extent. Similar to our five senses - sight, sound, smell, taste and touch -correspondingly visual/optical, acoustic/ultrasonic, electrical, chemical and thermal/magnetic sensors have been developed. The response from these primary sensors is converted to electrical signals, which are transmitted to the brain (central processing unit) for further processing. In addition to the processing, the role of the processor is to make decision based on these inputs. This is currently done manually by an experienced operator who has an understanding of the sensing and processing technology. To aid the operator in making a more judicious decision, the conditioned signal has to be presented with as much pertinent information displayed in an arresting way. A further development would be to provide the virtual machine itself to make the judgment - smart sensor. The next stage in this would be for the processor to decide on the course of action and the actuation mechanism to respond accordingly. Virtual human robots can be equipped with sensors, memory, perception, and behavioural motor. This eventually makes these virtual human
robots to act or react to events. The design of a behavioural animation system raises questions about creating autonomous actors, endowing them with perception, selecting their actions, their motor control and making their behaviour believable and the behaviour should be spontaneous and unpredictable.
Keywords- smart materials, structures, smart sensors, actuators.
INTRODUCTION
There is an increasing awareness of the benefits to be derived from the development and exploitation of smart materials and structures in applications ranging from hydrospace to aerospace. With the ability to respond autonomously to changes in their environment, smart systems can offer a simplified approach to the control of various material and system characteristics such as light transmission, viscosity, strain, noise and vibration etc. depending on the smart materials used [1]. There are a number of materials that act as both sensors and actuators that can monitor and respond to their environment. However, with the ability to also modify their properties in response to an environmental change, they can be 'very smart' and, in effect, learn. While the scope of sensors and actuators is quite broad, three main sub-programs have been identified “ Smart Structures and Materials, Miniature Sensor and Actuators and Automated Testing, Inspection Monitoring and Evaluation. These are exciting times for Sensors and Actuators with the maturing of the enabling technologies of Photonics and Electronics paving the way for inventive and innovative system designs. For the modelling of sensor behaviours, the ultimate objective is to build intelligent autonomous virtual humans with adaptation, perception and memory. These virtual humans should be able to act freely and emotionally. They should be conscious and unpredictable. The virtual humans are expected in the near future to represent computer the concepts of behaviour, intelligence, autonomy, adaptation, perception, memory, freedom, emotion, consciousness, and unpredictability. Behaviour for virtual humans may be defined as a manner of conducting themselves. It is also the response of an individual, group, or species to its environment.
Intelligence may be defined as the ability to learn or understand or to deal with new or trying situations[1].
A. Mechatronic devices
The essential ingredients of any robotic system are sensors, computation and actuators. Appropriate choices of sensors and actuators can simplify a robotic system or may even be the difference between its success and failure. Mechatronic devices are the novel actuators including those based on shape memory alloy, electrorheological fluids, magnetic fluids and the piezoelectic effect as well as a wide range of sensors for measuring quantities of importance for robotic systems [1].
B. Robotic mechanisms
All of the sensors, actuators [1]-[2] and algorithms that are developed should be tested by incorporating them into a mobile robot platform, humanoid robot or fixed manipulator/ gripper system. An extensive experience of building legged, wheeled and tracked land vehicles, submersibles and flying robots as well as robotic grippers and complete humanoid robots are required.
II. VIRTUAL REALITY APPLICATION
Virtual human robots (Fig. 1) can be equipped with sensors, memory, perception, and behavioral motor. This eventually makes this to act or react to events. The design of a behavioral animation system raises questions about creating autonomous actors, endowing them with perception, selecting their actions, their motor control and making their behaviour believable and the behavior should be spontaneous and unpredictable. They should give an illusion of life, making the people believe that that they are really alive. A virtual human can be developed which include the basic components of a smart system embedded sensor(s), an information processing (software) system for data analysis, logic and decision making and system hardware (e.g., multiplexers, actuators
etc) interfaced to a computer for control, actuation and feedback [4].
III. SENSORS AND ACTUATORS
Development of the research and technology base in Sensors and Actuators (Fig. 2) requires a basic understanding of the principles and mechanics of the components. Programs identified within the Sensors and Actuators SRP, include
* Optical Sensors and Digital Imaging
* Smart Materials and Structures
* Non-Destructive Testing and Evaluation
* Bio-chemical Sensors
* Other related programmes
Being a fairly broad discipline, the Sensors and Actuators SRP has common ground and overlap with most of the other SRP's. For example, with the MEMS programme, there is the development of optical sensors for characterization and reliability of MEMS devices. Similarly a suite of techniques is developed for NDT and stress management of electronic packaging systems. With the biomedical group, there is work on development of fiber optic biosensors for bacterial sensing and detection. While the research focus is on development of novel sensors and actuators, industrial support requires integrated system development as well. The Smart Structures and Materials program is a particular case in point of an integrated system incorporating sensors, processing and decision making capabilities and actuation. It can be defined as "a system or material which has built-in or intrinsic sensor(s), actuator(s), and control mechanism(s) whereby it is capable of sensing a stimulus, responding to it in a predetermined manner and extent, in a shortlappropriate time, and reverting to its original state as soon as the stimulus is removed". The term stimulus may include stress, strain, incident light, electric field, gas molecules, temperature, hydrostatic pressure etc. whereas, the response could be any of a number of possibilities, such as motion or change in optical properties, conductivity, surface tension,
dielectric, piezoelectric or pyroelectric properties, mechanical modulus or permeability [5]. Although Japanese and American scientists have rather different views of smart/intelligent materials, they are generally regarded to be a group of materials that have varying degrees of sensing and actuating functions that can be incorporated into systems having feedback loops to constantly vary or "tune" one or more material property such as size, shape, color, structure or composition. Using sophisticated hardware (control devices e.g., actuators) and software these materials can be incorporated into what is described as a smart/intelligent system, that possesses a higher level of intelligence such as selfdiagnosis, self-repair, learning ability, ability to discriminate shapes and forms, ability to judge etc.
A. Optical Sensors and Digital Imaging
Optical components such as optical fibers, lasers and detectors are only recently being
developed fueled by the applications in the communications industry. Electronics and Optics have been competing technologies in sensor and actuator system over the years. Indeed, the evolution of electronics and optics has taken similar routes. Optical Sensors offer some advantages over electrical sensors, such as use of passive, dielectric and insulating components. No electrical power at the measurement point is required, thus no heat generation, electrical shorting and fire hazard problems. Remote non-contact sensing and whole-field visual display of the measure and rounds of the positive aspects of optical sensors. However, electrical sensors have a longer industrial history and thus components and devices for these sensors are readily available. Thus electrical sensors are more prevalent. The cost of these components is competitive and various off-the-shelf systems are becoming available. Optoelectronics has merged these two competing technologies, taking the best of each. Optics has the advantage in the primary sensing capabilities, while electronics is currently leading in the processing and actuating technologies. Thus this has a lot to offer in development of novel sensor processor- actuator systems [6].
B. Environmental Requirements
The sensor implanted humanoid has to survey the construction and, if possible, the whole life span of the structure. During the construction phases, the sensor is exposed to a hostile environment and has therefore to be rugged enough to protect the fibers from external agent. Chemical aggression has to be taken into account since concrete can be particularly aggressive because of its high alkalinity. These requirements are often contrasting with the ones of the previous point. To protect the fiber one tends to isolate if from the environment by using thicker or multiple layers of coating. This has the side effect to impede the strain transmission from the structure to the fiber. Finally, the sensor must be easy to use by humanoid and has to be installed rapidly without major disturbance to the building yard schedule respond to all these requirements. Humanoids may be embedded with all these requirements so that the sensors can either be embedded into concrete, installed on the surface of an existing structure or secured inside a borehole by grouting.
The current investigations on the fiber optics are
* Studying the feasibility of using a fiber optic sensor (Fig.3) for measuring strain.
* Experimentally determining the sensibility of fiber optic soil strains sensors.
* Developing a fiber optic sensor, this can measure the visco elastic strain and permanent deformation of soil.
* Studying the effect of soil moisture content on the ability of the fiber optic sensor to measure soil strains.
The Disadvantages that counts includes,
* Sensors should be handled with care and Fibre optic sensors are still more expensive.
* Special skills are needed while installing the sensors.
With the advent of smart/intelligent materials and their applications on structures which are known as smart/intelligent structures result in value addition of structures in terms of operational, functional serviceability during their use as a structural member of a building or any other equipment, vehicle etc. This technique also helps in monitoring of structures during their service and indicates the defects, damages occur in their use in the form of cracks, delaminations, deformations etc. which is very useful in assessing the suitability and fitness of a structure in rendering further service for their remaining life. Though this technique is quite evidently gaining momentum in their applications in the field manufacturing, robotics, evidently gaining momentum in their applications in the fIeld manufacturing, robotics, materials but its use in civil engineering structures is yet to gain attention of the designers and constructors. As the construction cost of the civil engineering structures is escalating and also subjected to natural calamities like earthquakes, forces of wind, weathering etc. its structural fitness has to be established from time to time for its sustainable serviceability and structural adequacy by applying smart materials concepts [2]-[3].
C. Ceramic-based Actuator Materials
It has been tacitly assumed to this point that all actuator materials behave similarly. In broad terms, some actuators are developed using piezoelectric materials whereas others exploit electrostrictive materials based on relaxor ferroelectrics. In addition, within the piezoelectric materials there is considerable variation in how each material responds to an applied voltage which is a reflection of both their composition and microstructure. Smart Materials represent an enabling technology that has applications across a wide range of sectors including construction, transportation, agriculture, food and packaging, healthcare, sport and leisure, white goods, energy and environment, space, and defence. Smart Materials are materials that sense their environment and respond. Research and Development project and implimentations to incorporate Humanoids in the following application areas include
* Modern Built-Environment
* Environmentally Friendly Transport
* Sustainable Production and Consumption
IV. BACKGROUND
Smart Materials are materials that respond to environmental stimuli, such as temperature, moisture, pH, or electric and magnetic fields. For example, photochromic materials that change colour in response to light; shape memory alloys and polymers which change/recover their shape in response to heat and electro- and magnetorheological fluids that change viscosity in response to electric or magnetic stimuli. Smart Materials can be used directly to make smart systems or structures or embedded in structures whose inherent properties can be changed to meet high value-added performance needs. Smart Materials technology is relatively new to the economy and has a strong innovative content. According to work by the Materials Foresight Panel, the use of smart materials could make a significant impact in many market sectors. In the food industry, smart labels and tags could be used in the implementation of traceability protocols to improve food quality and safety e.g. using thermo chromic ink to monitor temperature history. In construction, smart materials and systems could be used in 'smart' buildings, for environmental control, security and structural health monitoring e.g. strain measurement in bridges using embedded fibre optic sensors (Fig. 4). Magneto-rheological fluids have been used to damp cable-stayed bridges and reduce the effects of earthquakes. In aerospace, smart materials could find applications in 'smart wings', health and usage monitoring systems (HUMS), and active vibration control in helicopter blades. In marine and rail transport, possibilities include strain monitoring using embedded fibre optic sensors. Smart textiles are also finding applications in sportswear that could be developed for everyday wear and for health and safety purposes [8]-[12].
A. Structural Health Monitoring
Virtual human robots can be equipped with sensors, memory, perception, and behavioral motor. This eventually makes these virtual human robots to act or react to events.
* Also called Damage Detection
* Using response signals to determine if there has been a change in the system's parameters.
* Mathematically very much like parameter identification in many respects
* Numerous methods have been proposed.
* Impact is high for SMH systems that work without taking the base system out of operation.
B. Smart Structures
Key areas of focus for the development of smart structures to include: Miniaturisation and integration of components, e.g. application of sensors or smart materials in components Robustness of the smart system, e.g.interfacial issues relating to external connections to smart structures Device fabrication and manufacturability, e.g. Electrorheological fluids in active suspension systems, applications in telematics and traffic management Structural health monitoring, control and lifetime extension (including self-repair) of structures operating in hostile environments, e.g. vibration control in Aerospace and Construction applications. Thermal management of high temperature turbines for power generation. Selfmonitoring, self-repairing, low maintenance structures, e.g. bridges and rail track Smart structures that can self-monitor internal stresses, strains, creep, corrosion and wear would deliver significant benefits.
Projects can be based on any material format (e.g. speciality polymers, fibres and textiles, coatings, adhesives, composites, metals, and inorganic materials), which incorporate sensors or active functional materials such as: piezoelectrics, photochromics, thermochromics, electro and magneto rheological fluids, shape memory alloys, aeroelastictailored and other auxetic materials. For the modelling of actor behaviors, the ultimate objective is to build intelligent autonomous virtual humans with
adaptation, perception and memory. These virtual humans should be able to act freely and emotionally. They should be conscious and unpredictable. But can we expect in the near future to represent in the computer the concepts of behavior, intelligence, autonomy, adaptation, perception, memory, freedom, emotion, consciousness, and unpredictability [9]-[10].
C. Key Points
* This is the first successful trial in the worldto remotely control a man emulating robot soas to drive an industrial vehicle (backhoe) outdoors in lieu of a human operator.
* Furthermore, the robot's operation was controlled while having it wear protective clothing to protect it against the rain and dust outside. This too marks a world-first success demonstrating the robot's capability of performing outdoor work even in the rain.
* This has been achieved with an HRP- IS robot whose Honda R&D made hardware was provided with control software developed by the AIST.
* The robot has a promising application potential for restoration work in environments struck by catastrophes and in civil engineering and construction project and implimentation sites where it can "work" safely and smoothly.
D. Outline
This robot was remotely controlled to perform outdoor work (Fig.5) tasks normally carried out by human operators involving the operation (driving and excavation) of a vibrating industrial vehicle (backhoe) in the seated position. Furthermore, operation was
achieved with the robot wearing protective clothing to protect against rain and dust. This also marks a world first success indicating the robot's ability to carry out outdoor work tasks even in the rain. These results were achieved thanks to the development of the following three technologies:
* The "remote control technology" for instructing the humanoid robot to perform total body movements under remote control and the "remote control system" for executing the remote control tasks (KHI).
* The "protection technology" for protecting the humanoid robot against shock and vibrations of its operating seat and against the influences of the natural environment such as rain and dust (Tokyo Construction).
* The "full-body operation control technology" for controlling the humanoid robot's total body work movements with autonomous control capability to prevent the robot from falling. There have been many attempts until the present to robotize the industrial vehicles (including backhoes) themselves for work on sites requiring their operation
in dangerous work areas or in adverse environments. In contrast, the use of a humanoid robot to operate the industrial vehicle instead of a human operator has two distinct advantages:
* This means that robot does not only drive the vehicle but is also capable of executing the attendant work tasks (alighting from the vehicle to check the work site, carrying out simple repairs, etc.) and
* It permits the robotizing of all industrial vehicles without needing to modify them. Once humanoid robots (Fig. 5) now engaged in other types of work can be used, when necessary, for operational duties normally performed by human operators there will be a definite chance for a greater expansion of the humanoid robot market which in
turn holds promise of further reductions in their production and operating costs. The major insight gained from this success that has demonstrated the humanoid robot's ability to replace the human operator in operating (driving and excavation duties) commercially used industrial vehicles (backhoe) under remote control is the realization that humanoid robots are capable of moving in the same manner as humans. The humanoid robot's ability to carry out outdoor work tasks even in the rain by "wearing" protective clothing has widened the scope of the environmental conditions in which it is capable of executing work. From these two aspects there is every reason to expect that these results will make a substantial contribution toward the realization of practical work-performing humanoid robots. The development tasks ahead will include work to create wireless remote control and achieve a robot capable of boarding the industrial vehicle independently.
V. SMART MATERIALS AND STRUCTURE
SYSTEM
The use of smart materials (Fig-6) could make a significant impact in many market sectors. In the food industry, smart labels and tags could be used in the implementation of traceability protocols to improve food quality and safety e.g. using thermochromic ink to monitor temperature history. In construction, smart materials and systems could be used in 'smart' buildings, for environmental control, security and structural health monitoring e.g. strain measurement in bridges using embedded fibre optic sensors. Magneto-rheological fluids have been used to damp cable-stayed bridges and reduce the effects of
earthquakes. In aerospace, smart materials could find applications in 'smart wings', health and usage monitoring systems (HUMS), and active vibration control in helicopter blades. In marine and rail transport, possibilities include strain monitoring using embedded fibre optic sensors. Smart Structures, e.g. structures, with integrated sensors and actuator materials, which might eliminate the need for heavy mechanical actuation systems or damping systems through their functionality for shape change or vibration control. Self-monitoring, Control and Selfrepair, e.g. applications of functionally graded layers capable of a response tailored to their environment. This will involve use of sensor and actuator technologies for automatic control of conditions within buildings for comfort and energy savings, tagging for food packaging and for crime prevention application of sensors or smart materials in components Robustness of the smart system, e.g. interfacial issues relating to external connections to smart structures Device fabrication and manufacturability, e.g. electro-rheological fluids in active suspension systems, applications in telematics and traffic management Structural health monitoring, control and lifetime extension (including self-repair) of structures operating in hostile environments, e.g. vibration control in Aerospace and Construction applications. Projects can be based on any material format (e.g. speciality polymers, fibres and textiles, coatings, adhesives, composites, metals, and inorganic materials), which incorporate sensors or active functional materials such as: piezoelectrics, photochromics, thermochromics, electro and magneto rheological fluids, shape memory alloys, aeroelastictailored and other auxetic materials [10]-[1 1]. The potential application areas of smart materials and structures are very widespread and include energy - conservation, expensive systems with high potential for operational savings, e.g. transportation systems
such as aircraft or automobiles, aerospace structures, civil infrastructure, structural health monitoring, intelligent highways, high-speed railways, active noise suppression, robotics. In order to increase the speed of the railway vehicle and reduce the energy consumption, the vehicle body needs to be designed as light as possible, for heavy bodies result in limitations in the operating speed and requires actuators of increased size and power, so the flexibility of the structure becomes an important issue. Besides railway vehicles, flexible structures are also considered important in many other areas such as road vehicles, robotics and especially aerospace structures. the use of smart materials to minimize vibrations via robust control. Thus the aim of the proposed research is to contribute to the improvement of the performance of a flexible body of railway vehicles through the use of humanoid enabled smart materials to minimize vibrations via robust control. In order to achieve the aim, the tasks of research may include the following
* Rigorous study of flexible-bodies and smart materials (feasibility study)
* Modeling of the flexible body controlled via smart materials. Model reduction will be considered to reduce the complexity of the model.
* Development of appropriate control strategies
* Demonstration, evaluation and validation The idea of incorporating humanoid enabled smart materials into flexible structures to achieve improved performance of the flexible structure with application to railway flexible bodies. The motivation for the proposed research is introduced and tasks that may be involved in this research.
A. Characteristics of Sensor for Strain measurement
Optical fibre sensing systems (Fig.4) will be significantly less expensive than the conventional counterparts than the future, particularly those that are commercialized and produced in large quantities. Since a light signal rather than the electric current is carried, optical fibre sensors have very little loss and are immune to lighting damages. Mostly these sensors are based on the principle of white light interferometry. Some of the Fibre Optic Sensors are
SOFO displacement sensor
Bragg grating strain sensor
Micro bending displacement sensor
Fabry perot strain sensor
Raman distributed temperature sensor
B. Determination of Displacement by using SOFO Sensors
It is a fiber optic displacement sensor with a resolution in the micrometer range and has an excellent long-term stability. The measurement setup uses low-coherence interferometry to measure the length difference between two optical fibers installed on the structure to be monitored. The measurement fiber is pre tensioned and mechanically coupled to the structure at two anchorage points in order to follow its deformations, while the reference fiber is free and acts as temperature reference. Both fibers are installed inside the same pipe and the measurement basis can be chosen between 200mm and 10m.The resolution of the system is 2 micrometer independently from the measurement basis and its measurement basis and its precision is of 0.2% of 12 the measured deformation even over years of operation .The SOFO system (Fig.7) has been successfully used to monitor more than 50 structures including bridges, tunnels, piles, dam, nuclear power plant etc. [9]
VI. CONCLUSION
Sensors are playing a vital role in all sorts of sciences. Hence, instead of placing various sensors at variable places in various application areas, it may be better to embed these sensors in humanoids and it could be effectively used in detecting, monitoring, message
conveying, repairing etc., Thus the mobility of humanoids may be used effectively. A smart intelligent structure includes distributed actuators, sensors and microprocessors that analyze the response from the sensors and use distributed parameter control theory to command actuators, to apply localized strains. A smart structure has the capacity to respond to a changing external environment such as loads, temperatures and shape change, as well as to varying internal environment i.e., failure of a structure. This technology has numerous applications much as vibration and buckling control, ape control, damage assessment and active noise control. Smart structure techniques are being increasingly applied to civil engineering structures for health monitoring of buildings with strain and corrosion sensors.
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
Reply
seminar presentation
Active In SP
**

Posts: 582
Joined: Apr 2010
#3
18-05-2010, 08:50 PM


.docx   smart material by Maulik Bhatt.docx (Size: 672.38 KB / Downloads: 411)

Summary
Materials science isn
Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
Reply
science projects buddy
Active In SP
**

Posts: 278
Joined: Dec 2010
#4
03-01-2011, 06:38 PM

Smart Materials Concepts & Applications
Submitted by:

SAMSON T.
DEPARTMENT OF MECHANICAL ENGINEERING
COLLEGE OF ENGINEERING TRIVANDRUM
August 2010



ABSTRACT


`Smart' materials have the ability to perform both sensing and actuating
functions. Passively smart materials respond to external change in a useful
manner without assistance, while actively smart materials have a feedback loop
which allows them to both recognize the change and initiate an appropriate
response through an actuator circuit. One of the techniques used to impart
intelligence into materials is `Biomimetics', the imitation of biological functions
in engineering materials. Composite ferroelectrics fashioned after the lateral line
and swim bladders of fish are used to illustrate this idea. `Very smart' materials,
in addition to sensing and actuating, have the ability to `learn' by altering their
property coefficients in response to the environment. Field-induced changes in
the nonlinear properties of relaxor ferroelectrics and soft rubber are utilized to
construct tunable transducers. Integration of these different technologies into
compact, multifunction packages is the ultimate goal of research in the area of
smart materials

New 'smart' materials are being developed which can alter their properties
automatically in response to changes in the environment. Effects such as colour
changes can be produced from stimuli such as temperature. Other 'smart'
materials can adapt to their environments in a similar way to plants, with
actuators and sensors integrated into structural materials such as concrete and
steel, allowing the materials to monitor themselves. Designers are in a position to
identify needs and develop the best specifications for new materials. Truly
intelligent materials could be available in early 21st century, with technology for
manipulating molecular order in materials rapidly advancing.


.pdf   Smart Materials Concepts and applications.pdf (Size: 398.41 KB / Downloads: 429)

VII 1.0 INTRODUCTION

`Smart' materials have the ability to perform both sensing and actuating
functions. Passively smart materials respond to external change in a useful
manner without assistance, while actively smart materials have a feedback
loop which allows them to both recognize the change and initiate an
appropriate response through an actuator circuit. One of the techniques used
to impart intelligence into materials is `Biomimetics', the imitation of
biological functions in engineering materials. Composite ferroelectrics
fashioned after the lateral line and swim bladders of fish are used to illustrate
this idea. `Very smart' materials, in addition to sensing and actuating, have
the ability to `learn' by altering their property coefficients in response to the
environment. Field-induced changes in the nonlinear properties of relaxor
ferroelectrics and soft rubber are utilized to construct tunable transducers.
Integration of these different technologies into compact, multifunction
packages is the ultimate goal of research in the area of smart materials

Materials that have one or more properties that can be significantly
changed in a controlled fashion by external stimuli, such as

¾ stress
¾ temperature
¾ electric or magnetic fields.

1The main advantages of the smart materials are the following:
¾ No moving parts
¾ High reliability
¾ Low power requirements, etc
¾ High energy density (compared to pneumatic and hydraulic
actuators)
¾ Excellent bandwidth

Classification of Smart Materials
¾ Actuating Materials
o Electrorheological Fluids (ER Fluids)
o Shape Memory Alloys (SMA)
¾ Sensing Materials
o Fiber Optic (F.O.) sensors
¾ Dual-Purpose Materials (Actuating & Sensing)
o Magnetostrictive Materials
¾ Piezoelectric Materials

2 2.0 CLASSIFICATION


Material Type
¾ Shape memory alloys
¾ Piezoelectric
¾ Electrostrictive
¾ Magnetostrictive materials
¾ Fiber-optic sensor systems
¾ Conductive polymers
¾ Chromogenic materials and systems:
¾ Thermo chromic
¾ Electro chromic
¾ Controllable fluids:
¾ Electro rheological
¾ Magneto rheological
¾ Biomimetic polymers and gels
¾ Fullerenes and carbon nanotubes


33.0 PIEZOELECTRIC MATERIALS
Fig: 1 – Piezoelectric Principle
The piezoelectric effect describes the
relation between a mechanical stress and an
electrical voltage in solids.
It is reversbile: an applied mechanical stress
will generate a voltage and an applied
voltage will change the shape of the solid by
a small amount (up to a 4% change in
volume). In physics, the piezoelectric effect
can be described as the the link between electrostatics and mechanics.

History
The piezoelectric effect was discovered in 1880 by the Jacques and Pierre
Curie brothers. They found out that when a mechanical stress was applied on
crystals such as tourmaline, tourmaline, topaz, quartz, Rochelle salt and cane
sugar, electrical charges appeared, and this voltage was proportional to the
stress. First applications were piezoelectric ultrasonic transducers and soon
swinging quartz for standards of frequency (quartz clocks). An everyday life
application example is your car's airbag sensor. The material detects the
intensity of the shock and sends an electricla signal which triggers the airbag.

Piezoelectric materials
The piezoelectric effect occurs only in non conductive materials. Piezoelectric
materials can be divided in 2 main groups: crystals and cermaics. The most
well-known piezoelectric material is quartz (SiO2).
4 4.0 ELECTROSTRICTIVE MATERIALS

These materials can also change their dimensions on the application of
an electric field. Although the changes thus obtained are not linear in either
direction, these materials have widespread application in medical and
engineering fields.
Electrostriction is a property of all dielectric materials, and is caused by
the presence of randomly-aligned electrical domains within the material.
When an electric field is applied to the dielectric, the opposite sides of the
domains become differently charged and attract each other, reducing
material thickness in the direction of the applied field (and increasing
thickness in the orthogonal directions due to Poisson's ratio). The resulting
strain (ratio of deformation to the original dimension) is proportional to the
square of the polarization. Reversal of the electric field does not reverse the
direction of the deformation.
Electrostrictive materials, such as the ceramic PMN/PT/La
(0.9/0.1/1%), operating above Tmax with a DC bias field behave as a
piezoelectric ceramic material with C<is proportional to> symmetry. The
effective piezoelectric and electromechanical coupling coefficients are found
to be linear as a function of the DC bias field up to about 0.5MV/m, while the
elastic constant (at constant field) and the dielectric constant (at constant
stress) are found to have a quadratic dependence on the DC bias field. Above
0.5 MV/m the piezoelectric and the electromechanical coupling constants
begin to saturate due to higher 4th order electrostriction (S <is proportional
to> kE4, k negative) In essence these materials behave as tunable
piezoelectric materials with the piezoelectric coefficient being directly
proportional to the electrostrictive coefficient and the DC bias field (d3 =
2Q33EDC) up to saturation. The properties of DC biased resonators of this
5material are derived from a nonlinear theory based on the Taylor's series
expansion of the thermodynamic potentials to 3rd and higher order terms in
field and stress. The resonance equations for the DC biased length
extensional (LE) resonator are presented and it is shown that DC biased
resonance techniques can be used to measure the electrostrictive and other
higher order coefficients at frequencies of interest to tbe ultrasonics
community. The experimental apparatus used to measure these properties
will be described and the limitations with regards to isolation of the
measurement signal and the DC bias signal will be discussed. We will show
that these materials, in conjunction with standard piezoelectric ceramics,
offer the transducer design engineer an extra degree of freedom and the
feasibility of unique transducer designs that will allow, for example, multiple
beam patterns from the same circular/linear array using an adjustable DC
bias profile on the array or tbe possible use of the field dependence of the
compliance to fabricate electrically active backing materials. In conclusion
we discuss how a better understanding of the macroscopic theory of
piezoelectric and electrostrictive materials can benefit the transducer
designer.
65.0 MAGNETOSTRICTIVE MATERIAL

These are quite similar to Electrostrictive materials, except for the fact
that they respond to magnetic fields. The most widely used Magnetostrictive
material is TERFENOL-D, which is made from the rarest of the rare earth
elements, i.e. Terbium. This material is highly non-linear and has the
capability to produce large strains.
Magnetostrictive (MS) technology and Magneto-Rheological Fluid
(MRF) technology are old “newcomers” coming to the market at high speed.
Various industries including the automotive industry are full of potential MS
and MRF applications. Magnetostrictive technology and Magneto-
Rheological Fluid technology have been successfully employed already in
various low and high volume applications. A structure based on MS might be
the next generation in design for products where power density, accuracy
and dynamic performance are the key features. Since the introduction of
active (MS) materials such as Terfenol-D, with stable characteristics over a
wide range of temperatures and high magnetoelastic properties, interest in
MS technology has been growing. Additionally, for products where there is a
need to control fluid motion by varying the viscosity, a structure based on
MRF might be an improvement in functionality and costs.
Two aspects of this technology, direct shear mode (used in brakes and
clutches) and valve mode (used in dampers) have been studied thoroughly
and several applications are already present on the market. Excellent
features like fast response, simple interface between electrical power input
and mechanical power output, and precise controllability make MRF
technology attractive for many applications.
7Magnetostriction effects

Crystals of ferromagnetic materials change their shape when they are
placed in a magnetic field.. This phenomenon is called magnetostriction. It is
related to various other physical effects. Magnetostriction is, in general, a
reversible exchange of energy between the mechanical form and the
magnetic form. The ability to convert an amount of energy from one form
into another allows the use of magnetostrictive materials in actuator and
sensor applications.
8 6.0 RHEOLOGICAL MATERIALS

These fluids may find applications in brakes, shock absorbers and
dampers for vehicle seats. These can be fitted to buildings and bridges to
suppress the damaging effects, for example, high winds or earthquakes.


Fig. 2 Rheological Materials


Rheology is the study of the flow of matter: primarily in the liquid
state, but also as 'soft solids' or solids under conditions in which they
respond with plastic flow rather than deforming elastically in response to an
applied force. It applies to substances which have a complex molecular
structure, such as muds, sludges, suspensions, polymers and other glass
formers (e.g. silicates), as well as many foods and additives, bodily fluids (e.g.
blood) and other biological materials.
The flow of these substances cannot be characterized by a single value of
viscosity (at a fixed temperature). While the viscosity of liquids normally
9varies with temperature, it is variations with other factors which are studied
in rheology. For example, ketchup can have its viscosity reduced by shaking
(or other forms of mechanical agitation) but water cannot. Since Sir Isaac
Newton originated the concept of viscosity, the study of variable viscosity
liquids is also often called Non-Newtonian fluid mechanics.

An electro-rheological fluid is a material in which a particulate
solid is suspended in an electrically non-conducting fluid such as oil. On
the application of an electric field, the viscosity and other material
properties undergo dramatic and significant changes. In this paper, the
particulate imbedded fluid is considered as a homogeneous continuum.
It is assumed that the Cauchy stress depends on the velocity gradient
and the electric field vector. A representation for the constitutive
equation is developed using standard methods of continuum mechanics.
The stress components are calculated for a shear flow in which the
electric field vector is normal to the velocity vector. The model predicts
(i) a viscosity which depends on the shear rate and electric field and
(ii) normal stresses due to the interaction between the shear flow and
the electric field. These expressions are used to study several
fundamental shear flows: the flow between parallel plates, Couette flow,
and flow in an eccentric rotating disc device. Detailed solutions are
presented when the shear response is that of a Bingham fluid whose
yield stress and viscosity depends on the electric field.
107.0 THERMORESPONSIVE MATERIALS
Thermoresponsive materials are sometimes also known as shape
memory alloys or shape memory polymers. These materials alter their shape
under the influence of the ambient temperature.

Magnetic Shape Memory Alloys
Like thermoresponsive materials that alter their shape under the
influence of the ambient temperature, magnetic shape memory alloys change
shape due to changes in magnetic fields.

Polychromic, Chromogenic or Halochromic Materials
Polychromic, chromogenic and halochromic materials all change
colour due to external influences. These external influences can be
alterations in pH, temperature, light or electricity. Materials that change
colour due to temperature are normally known as thermochromic materials
and those that alter due to light are photochromic materials.

Applications of Smart Nanomaterials
Smart nanomaterials are expected to make their presence strongly felt
in areas like:
¾ Healthcare, with smart materials that respond to injuries by delivering
drugs and antibiotics or by hardening to produce a cast on a broken
limb.
¾ Implants and prostheses made from materials that modify surfaces and
biofunctionality to increase biocompatibility
¾ Energy generation and conservation with highly efficient batteries and
energy generating materials.
¾ Security and Terrorism Defence with smart materials that can detect
11toxins and either render them neutral, warn people nearby or protect
them from it.
¾ Smart textiles that can change colour, such as camouflage materials
that change colour and pattern depending upon the appearance of the
surrounding environment. These materials may even project and implimentation an image
of what is behind the person in order to render them invisible.
¾ Surveillance using “Smartdust” and “Smartdust Motes” that are
nanosized machines housing a range of sensors and wireless
communication devices. Individually they can float undetected in a
room with other dust particles. By combining the information gathered
from hundreds, thousands or millions of these tiny specs can give a full
report on what is occurring with the area including sound and images.

Fig. 3 Shape Memory Alloys
128.0 ELECTROCHROMIC MATERIALS
Electrochromism is the phenomenon displayed by some materials of
reversibly changing color when a burst of charge is applied. Various types of
materials and structures can be used to construct electrochromic devices,
depending on the specific applications.
One good example of an electrochromic material is polyaniline which
can be formed either by the electrochemical or chemical oxidation of aniline.
If an electrode is immersed in hydrochloric acid which contains a small
concentration of aniline, then a film of polyaniline can be grown on the
electrode. Depending on the oxidation state, polyaniline can either be pale
yellow or dark green/black. Other electrochromic materials that have found
technological application include the viologens and polyoxotungstates. Other
electrochromic materials include tungsten oxide (WO3), which is the main
chemical used in the production of electrochromic windows or smart glass.
Polymer-based solutions have recently been developed by John Reynolds
and colleagues at the University of Florida. These promise to provide flexible
and cheap electrochromics in a variety of colours, going all the way up to
black.
Fig. 4 Electrochromic Materials
As the color change is persistent
and energy need only be applied to
effect a change, electrochromic
materials are used to control the
amount of light and heat allowed to pass
through windows ("smart windows"),
and has also been applied in the
automobile industry to automatically
tint rear-view mirrors in various lighting
13conditions. Viologen is used in conjunction with titanium dioxide (TiO2) in
the creation of small digital displays. It is hoped that these will replace liquid
crystal displays as the viologen, which is typically dark blue, has a high
contrast compared to the bright white of the titania, thereby providing the
display high visibility.
ICE 3 high speed trains use electrochromatic glass panels between the
passenger compartment and the driver's cabin. The standard mode is
clear/lucent and can be switched by the driver to frosted/translucent mainly
to keep passengers off "unwanted sights" for example in case of (human)
obstacles.





Fig. 10 Electrochromic
Materials


14 9.0 APPLICATION
¾ Fast response valves
¾ High power density hydraulic pumps
¾ Active bearings for reduction of machinery noise
¾ Footwear
¾ Sports equipment
¾ Precision machining
¾ Vibration and acoustic sensors
¾ Dampers, etc.
¾ Healthcare, with smart materials that respond to injuries by delivering
drugs and antibiotics or by hardening to produce a cast on a broken
limb.
¾ Energy generation and conservation with highly efficient batteries and
energy generating materials.
¾ Security and Terrorism Defence with smart materials that can detect
toxins and either render them neutral, warn people nearby or protect
them from it.
¾ Smart textiles that can change colour, such as camouflage materials
that change colour and pattern depending upon the appearance of the
surrounding environment. These materials may even project and implimentation an image
of what is behind the person in order to render them invisible.
¾ Surveillance using “Smartdust” and “Smartdust Motes” that are
nanosized machines housing a range of sensors and wireless
communication devices. Individually they can float undetected in a
room with other dust particles. By combining the information gathered
from hundreds, thousands or millions of these tiny specs can give a full
report on what is occurring with the area including sound and images.
1510.0 CONCLUSION

Optical-fibre crack-monitoring sensors are capable of detecting crack-
width up to 5µm. The technologies using smart materials are useful for both
existing and emerging technologies.
Smart Materials described here need further research to evolve the
design guidelines of systems.
The technologies using smart materials are useful for both new and
existing constructions. Of the many emerging technologies available the few
described here need further research to evolve the design guidelines of
systems. Codes, standards and practices are of crucial importance for the
further development.
Piezoelectrics and magnetostrictives are most effective for high
frequency control applications. Piezoelectrics for applications were size of the
element is of concern. Magnetostrictives are good when size is of no concern.
Shape memory alloys are very effective for low frequency vibration or shape
control. Electrorheological fluids are still being explored. Sandwich beams
are generally the only structural application
Fiber optic sensors are very effective in all application
1611.0 REFERENCE


→ Erin B. Murphy, Fred Wudl, “The world of smart healable materials”, Review
Article Progress in Polymer Science, Volume 35, Issues 1-2, January-February
2010, Pages 223-251
→ Frank Stajano a,*, Neil Hoult b,1, Ian Wassell a, Peter Bennett b, Campbell
Middleton b, Kenichi Soga b, Smart bridges, smart tunnels: Transforming wireless
sensor networks from research prototypes into robust engineering infrastructure,
Technical report, Federal Highway Administration, Turner- Fairbank Highway
Research Center, January 2008.
→ Giola B. Santoni, Lingyu Yu, Buli Xu, Victor Giurgiutiu, “Lamb Wave-Mode Tuning
of Piezoelectric Wafer Active Sensors for Structural Health Monitoring”,
Transactions of the ASME Vol. 129, DECEMBER 2007, PP. 752-762.
→ Victor Giurgiutiu, Andrei Zagrai, JingJing Bao, “Embedded Active Sensors for In-
Situ Structural Health Monitoring of Thin-Wall Structures”, Journal of Pressure
Vessel Technology, AUGUST 2002, Vol. 124, pp. 293-302.
→ K F Hale, “An optical-fibre fatigue crack-detection and monitoring system”, Smart
Mater. Struct. 1 (1992) 156-161.

Use Search at http://topicideas.net/search.php wisely To Get Information About Project Topic and Seminar ideas with report/source code along pdf and ppt presenaion
Reply
summer project pal
Active In SP
**

Posts: 308
Joined: Jan 2011
#5
08-01-2011, 11:18 PM

ABSTRACT

Smart or intelligent materials are materials that have the intrinsic and extrinsic capabilities, first, to respond to stimuli and environmental changes and, second, to activate their functions according to these changes. The stimuli could originate internally or externally. Since its beginnings, materials science has undergone a distinct evolution: from the use of inert structural materials to materials built for a particular function, to active or adaptive materials, and finally to smart materials with more acute recognition, discrimination and reaction capabilities. To encompass this last transformation, new materials and alloys have to satisfy a number of fundamental specifications. Smart materials can come in a variety of sizes, shapes, compounds, and functions. But what they all share— indeed what makes them “smart”—is their ability to adapt to changing conditions. Smart materials are the ultimate shape shifters. They can also alter their physical form, monitor their environment, and even diagnose their own internal conditions. They can also do all of this while intelligently interacting with the objects and people around them. The components of the smart materials revolution have been finding their way out of the labs and into industrial applications for the past decade.

.doc   Smart Materials.doc (Size: 740 KB / Downloads: 224)
passwordConfusedeminar and presentationproject and implimentations
CONTENTS

1. INTRODUCTION
2. USES & APPLICATIONS
3. SMART MATERIALS AND SMART SYSTEMS FOR THE FUTURE
4. SMART STRUCTURES
5. MILITARY APPLICATIONS
6. THE POTENTIAL BENEFITS
7. STRUCTURAL APPLICATION OF SMART MATERIALS
8. CONCLUSION



1. INTRODUCTION

1. 1 SMART MATERIALS

Over the past century, we have learned how to create specialized materials that meet our specific needs for strength, durability, weight, flexibility, and cost. However, with the advent of smart materials, components may be able to modify themselves, independently, and in each of these dimensions. Smart materials can come in a variety of sizes, shapes, compounds, and functions. But what they all share— indeed what makes them “smart”—is their ability to adapt to changing conditions. Smart materials are the ultimate shape shifters. They can also alter their physical form, monitor their environment, and even diagnose their own internal conditions. They can also do all of this while intelligently interacting with the objects and people around them. More boldly, it is highly likely that once smart materials become truly ubiquitous—once they are seamlessly integrated into a webbed, wireless, and pervasive network —smart materials will challenge our basic assumptions about, and definitions of “living matter.”



A smart fluid developed in labs at the Michigan Institute of Technology


IMPORTANCE

In certain respects, smart materials are an answer to many contemporary problems. In a world of diminishing resources, they promise increased sustainability of goods through improved efficiency and preventive maintenance. In a world of health and safety threats, they offer early detection, automated diagnosis, and even self-repair. In a world of political terrorism, they may offer sophisticated biowarfare countermeasures, or provide targeted scanning and intelligence- gathering in particularly sensitive environments. In general, smart materials come in three distinct flavors: passively smart materials that respond directly and uniformly to stimuli without any signal processing; actively smart materials that can, with the help of a remote controller, sense a signal, analyze it, and then “decide” to respond in a particular way; and finally, the more powerful and autonomous intelligent materials that carry internal, fully integrated controllers, sensors, and actuators.



2. USES & APPLICATIONS

The components of the smart materials revolution have been finding their way out of the labs and into industrial applications for the past decade. As yet, they fall into several classes and categories: piezoelectrics, electrorestrictors, magnetorestrictors, shape-memory alloys, and electrorheological fluids. What these materials all have in common is the ability to act as both sensors and actuators. In some cases, when a force is applied to these smart materials, they “measure” the force, and “reverse” the process by responding with, or creating, an appropriate counter force. In other cases, the materials are populated by sensors that detect environmental conditions within the material itself. When conditions cross designated thresholds, the materials then send a signal that is processed elsewhere in the system. For instance, “smart concrete”—under development at the State University of New York at Buffalo—would be programmed to sense and detect internal hairline fissures. If these conditions are detected, the smart material would alert other systems to avoid a structural failure. Smart materials are currently used for a growing range of commercial applications, including noise and vibration suppression (noise-canceling headphones); strain sensing (seismic monitoring of bridges and buildings); and sensors and actuators (such as accelerometers for airbags). A number of companies, including The Electric Shoe Company and Compaq, are also exploring the use of smart materials. The Electric Shoe Company is currently producing piezoelectric power systems that generate electric power from the body’s motion while walking. Compaq is investigating the production of special keyboards that generate power by the action of typing. Descriptions of applications for the smart materials mentioned above suggest that their impact will be broadly felt across industries.

Piezoelectrics

Piezoelectric materials produce an electrical field when subject to a mechanical strain. Conversely, if an electrical field is applied to them, the material is stressed. Thus they can be used to generate low levels of power from simple mechanical motions or to deform surfaces in response to electrical signals. An excellent example of this is the application of smart materials in snow skis. Piezoelectric elements adjust the stiffness of the skis in response to conditions on the slope by damping shock and optimizing performance throughout a run.

Magnetorestrictors

These materials behave much like piezoelectrics, in that they are reciprocal devices that can both “receive” and “send” information within the systems that they inhabit. However, unlike piezoelectrics, magnetorestrictors respond to a magnetic field rather than an electric field. As such, they produce a magnetic field when strained. Applications for magnetorestrictors include machine tools, transducers, and sonar systems. Magnetorestrictors can also be used for vibration control (in factory equipment or automobiles), fuel injection systems, and the reconditioning (relining) of aged water and sewer pipelines.

Shape Memory Alloys (SMAs)

This special class of adaptive materials can convert thermal energy directly into mechanical work. For example, smart shape memory alloys can be “pro- Institute for the Future grammed” to adopt a specific shape when the alloy reaches a designated temperature (say, 100º Fahrenheit). This same alloy can then be manipulated or mechanically deformed to adopt a different shape when not in this designated temperature (say, when the material is at 50º Fahrenheit). In turn, when the alloy is heated above a critical transition temperature (approaching 100º), the material will “remember” its earlier shape and restore it—effectively converting the heat into mechanical work. Alternatively, SMAs can be trained to exhibit two shape-memory effects. In this case, heating the SMA results in one memorized shape while cooling results in a second, different shape (manipulation could then occur at a third, variable temperature).Shape Memory Alloys are currently used in various military applications. For instance, vibration-dampening SMAs, when deployed on supersonic fighter planes, decrease irrational stresses on materials, thereby increase the life and viability of the aircraft. SMAs can also be used preventively, to sense when materials are reaching critical failure limits. Commercially, SMAs can be used for vibration dampening effects on various factory machinery—say, within a component that holds a die-cutting laser. In this case, the drop in vibration interference radically increases the laser’s accuracy. SMA devices could also enhance fire detection equipment, or any other component or situation in which a change in temperature could trigger a necessary mechanical action. Of particular interest is potential application in surgical situations where device longevity, simplicity (ease of use), and biocompatibility could all be benefited.

Electrorheological Fluids

These materials represent fluid suspensions—emulsions wherein the smart material is dispersed, though not dissolved, within a liquid solution. When subjected to an electrical field, these suspensions experience reversible changes in rheological properties such as viscosity, plasticity, and elasticity. These reversible changes take place because of controllable interactions that occur between various micron-sized “smart-particles” suspended within the emulsion. Looking to the automotive industry, commercial advances in smart hydraulic fluids, networked car suspension systems, and smart shock-absorbers are already in development. Applying the above described interactions to, say, the smart shock-absorber, a sensor at the front of the car detects variations in the road surface. That signal is sent to a processor that determines whether the shock absorber should be more or less stiff. By altering the electrical field in the shock absorber, the viscosity of the ER fluid inside is also changed, tuning the suspension within milliseconds to match road conditions. Technological applications have been proposed for ER fluids in automotive clutches and d valves, servo drives, dampers, and brakes.

2.1 FUTURE INNOVATIONS

Consumer applications of smart materials in the coming decade will emphasize comfort and safety: noise Canceling (headphones and car interiors) as well as vibration canceling applications (car suspension systems) will no doubt be early winners, with some products already in the market. Industrial applications will provide increased control, consistency, and efficiency of distributed processes (for example, the management of print production at multiple international sites from a single, central location). In both cases, the magic of the materials will be largely behind-the-scenes and invisible to all but the engineers who design and maintain the systems. In the short term, smart-material adaptation will play out primarily as simple sensor-actuator responses to environmental stimuli. In the longer term, as the technology evolves, materials that self-diagnose and self-repair will find applications in everything from very small biomedical materials (internal components may someday automatically clean your arteries when necessary, or alert you of an oncoming bout of the flu), to very large-scale building materials that provide economies and efficiencies in an increasingly resource-constrained world. Another potential breakout in this technology is the use of deformable materials to create tactile user interfaces. Such developments may come in the form of flat-screen components (a flat screen that is both display and keyboard combined) that work in tandem with the subject matter they present. For instance, as you sit at your screen-unit an d link to your online banking accounts, unique keys that are context sensitive will beckon, raising up from the deformable screen surface, allowing you to perform specified commands and functions. As the task changes, so will the keys that present themselves.

The big commercial growth area for smart materials over the next decade is likely to be actively smart materials supported by a wireless infrastructure. This type of system will enable remote analysis and control of a wide range of sensors and actuators in many different environments. In some cases, these systems will be used to avoid sending workers into hazardous environments, but in others companies will deploy actively smart materials because they will be cost-effective. By decade’s end, intelligent materials will be routinely deployed in biomedical, military, and space applications. In these latter fields, it’s likely that the costs of innovation, and subsequent diffusion of the technology, will be subsidized by Government. Also by the end of the decade, watch for consumer markets in security and health applications to really come to the fore. Smart materials may act as sensors in these applications, notifying connected systems of abnormalities. Today’s relatively heavy heart monitor provided by cardiologists simply records signals for later analysis: smart materials will be capable of both sensing and transmitting anomalies in real time, thereby facilitating emergency response and treatment. Current military applications also hint at future possibilities for commercial applications.

Smart armoring of tanks, designed to diffuse the impacts of missiles, suggests strategies for shipping containers that protect their contents against damage. “Smart dust,” a new intelligence-gathering tool that employs a cloud of thousands of networked, floating camera-sensors (each “mote” is one millimeter square), spearheaded by Kris Pister and Randy Katz at University of California at Berkeley, hints at the future development of sensor arrays that could be deployed and utilized in environments that are hostile or dangerous to humans (such as the radioactive core of a nuclear reactor). Developers.


3. SMART MATERIALS AND SMART SYSTEMS FOR THE FUTURE

Smart systems trace their origin to a field of research that envisioned devices and materials that could mimic human muscular and nervous systems. The essential idea is to produce non-biological systems that will achieve the optimum functionality observed in biological systems through emulation of their adaptive capabilities and integrated design. By definition, smart materials and smart structures — and by extension smart systems — consist of systems with sensors and actuators that are either embedded in or attached to the system to form an integral part of it. The system and its related components form an entity that will act and react in a predicted manner, and ultimately behave in a pattern that emulates a biological function. The human body is the ideal or ultimate smart system. One of the first attempts to use the smart materials technology involved materials constructed to do the work of electromechanical devices. Since then, many types of sensors2 and actuators3 have been developed to measure or excite a system.

This technology is still in its infancy and the scientific community is just beginning to scratch the surface of its potential. With a bit of imagination one can see enormous benefits to society. This paper presents a simple overview of the technology. After defining what is meant by ‘smart materials’, it describes a smart structure and its components, and provides a few examples. This is part of an ongoing work on the use of smart materials for applications in engineering. A more detailed insight into smart structures and their applications is given elsewhere4. Today the drive to innovation is stronger than ever. Novel technologies and applications are spreading in all fields of science. Consequently, expectations and needs for engineering applications have increased tremendously, and the prospects of smart technologies to achieve them are very promising. Figure 1 summarizes these inter-relationships.



3.1 NEW MATERIAL REQUIREMENTS

To achieve a specific objective for a particular function or application, a new material or alloy has to satisfy specific qualifications related to the following properties

 technical properties, including mechanical characteristics such as plastic flow, fatigue and yield strength; and behavioral characteristics such as damage tolerance and electrical, heat and fire resistance
 technological properties, encompassing manufacturing, forming, welding abilities, thermal processing, waste level, workability, automation and repair capacities, economic criteria, related to raw material and reduction costs, supply expenses and availability
 environmental characteristics, including features such as toxicity and pollution; and sustainable development criteria, implying reuse and recycling capacities. If the functions of sensing and actuation are added to the list, then the new material/alloy is considered a smart material.










4. SMART STRUCTURES

As described earlier, a smart structure is a system that incorporates particular functions of sensing and actuation to perform smart actions in an ingenious way. The basic five components of a smart structure are summarized as follows (Figure 2):
Data Acquisition (tactile sensing): the aim of this component is to collect the required raw data needed for and appropriate sensing and monitoring of the structure.
Data Transmission (sensory nerves): the purpose of this part is to forward the raw data to the local and/or central command and control units.
Command and Control Unit (brain): the role of this unit is to manage and control the whole system by analyzing the data, reaching the appropriate conclusion, and determining the actions required.
Data Instructions (motor nerves): the function of this part is to transmit the decisions and the associated instructions back to the members of the structure.
Action Devices (muscles): the purpose of this part is to take action by triggering the controlling devices units.


DATA ACQUISITION

The sensing components of a smart structure are designed according to the nature of the event to be sensed radiation, magnetic, thermal, mechanical or chemical as well as according to the nature of the output required, such as thermal, magnetic, electrical, optical or mechanical. Other features considered are the size, geometry and mechanical properties of the required interface; the type of the environmental condition,such as corrosion, thermal, magnetic or electrical and, finally, the operational properties of the collected data such as sensitivity, bandwidth, linearity, gauge length, range. Fibre optics is an excellent example of sensors.

FIBRE OPTIC SENSING

Fibre optics is used as sensors that duplicate the action of conventional strain gauges. They respond to a change in transmitted light. This change could be in intensity, phase, frequency, polarization, wavelength or mode. They are highly sensitive, can detect minuscule variations and thus work very well. Three types of sensors are available: The Intensiometric type responds to any perturbation such as bending or twisting that changes the intensity of the transmitted light. These phase sensors come in a number of configurations and are highly sensitive to strains. The Michelson and Mach-Zehnder types use two fibers, one to sense and one as reference. They can measure strain over lengths in the order of meters. The Fabry-Perot type, which employs a single Fibre and reflectors, is based on the interference of light between two closely spaced surfaces. The Bragg grating type exploits spectroscopy, which is based on the modulation in the index of refraction along a short length of the fibers.. Figure 3 presents in a schematic way, a section of a smart bridge8.


ACTUATING COMPONENT

Like the sensing component, the actuating components are designed according to the nature of the required actuation — optical, magnetic, thermal, mechanical or chemical — as well as according to the nature of the driving energy, such as thermal, magnetic, electrical or chemical. Here also, environmental considerations such as thermal, magnetic or electrical properties sand corrosion, as well as the size, geometry and mechanical properties of the interface have to be considered. Finally, the properties of the actuators such as displacement, force generation, hysteretic, response time and bandwidth are also specified appropriately. Actuation can be produced by controlling devices such as actuators, pumps, heaters and dampers, and by a number of new materials such as those described previously.

SENSORS AND ACTUATORS

For active noise control applications, microphones are used as acoustic sensors and loudspeakers as acoustic actuators. For displacement and velocity control, two types of transducers are convenient: Linear Variable Differential Transformers (LVDT) and Linear Variable Inductance Transformers (LVIT). Other devices are also available— accelerometers and two basic types of actuators. Hydraulic and pneumatic actuators are employed when low frequency, large force and displacements are required, while the electromagnetic/ shaker types are utilized to react against an inertial electrodynamics mass.

COMMAND AND CONTROL UNIT

The command and control unit is the manager of day-to-day operations, responsible for monitoring the health and integrity of the system by means of a communication network which works in real time. The unit operates by controlling a compendium of integrated non-destructive evaluation instruments, by managing optical fibre sensors and actuators, or by overseeing operational and control devices. This is the brain of the smart structure and has two basic and distinct functions. The Processing Function. This function receives information; analyses it; sorts, arranges and classifies it; and stores and/or processes it depending on the nature, frequency and quality of the data and its origins. All these previous operations are dealt with by intelligent or smart processing, with or without human intervention, and with little or no human interaction. Special algorithms can be used to control the behavior or detect damage. Pattern recognition algorithms, as well as neural networks with fuzzy logic can be efficiently employed to process the raw data. Finally, expert systems can handle the retrieval, management, classification, and storage of the data. The Analysis Function. This function deals with the detailed examining of the raw data in an intelligent way. Using the analysis outlined above, it will exploit the results to assess the condition of the structure. This analysis consists of localizing and identifying specific variables, items or features as compared to threshold levels defined in advance, or specified in codes, rules, regulations or standards. When an adverse condition is detected and the appropriate corresponding conclusion is reached, decisions for action are sent to the action controlling devices, which will be triggered to react. Special algorithms are developed to operate these functions.

A FEW EXAMPLES

Vibration reduction in sporting goods. A new generation of tennis rackets, golf clubs, baseball bats(Figure 4) and ski boards have been introduced to reduce the vibration in these sporting goods, increasing the user’s comfort and reducing injuries.


Noise reduction in vehicles. Filaments of piezoelectric ceramic Fibre shaped into various geometries are used in conventional fabric or material processing to counter noise in vehicles, neutralizes shaking in helicopter rotor blades, or nullifies or at least diminishes vibrations in air conditioner fans and automobile dashboards. Spatial High Accuracy Position Encoding and Control System (SHAPECONS) incorporates smart components that were developed for the STEAR-9 Program (Figure 5).





5. MILITARY APPLICATIONS

There are number of distinctly military applications for the use of smart materials and smart systems can be delineated, among them:

Smart Skin. In battle soldiers could wear a T-shirt made of special tactile material that can detect a variety of signals from the human body, such as detection of hits by bullets. It can then signal the nature of the wound or injury, analyze their extent, decide on the urgency to react, and even takes some action to stabilize the injury.
Smart Aircraft. Figure 6 presents a few potential locations for the use of smart materials and structures in aircraft.
Autonomous Smart systems. Ground, marine or space smart vehicles will be a feature of future battles. These carriage systems, whether manned or unmanned, and equipped with sensors, actuators and sophisticated controls, will improve surveillance and target identification and improve battlefield awareness.
Stealth Applications. The smart vehicles mentioned above could be constructed using stealth technologies for their own protection: the B-2 stealth bomber or the F-117 stealth fighter is good examples of this technology. And, just as important, smart systems are needed for rapid and reliable identification of space or underwater stealth targets. The identification and detection of such targets, as well as the subsequent decision to take action with or without operator intervention, is another potential application of smart systems.


6. THE POTENTIAL BENEFITS

The potential future benefits of smart materials, structures and systems are amazing in their scope. This technology gives promise of optimum responses to highly complex problem areas by, for example, providing early warning of the problems or adapting the response to cope with unforeseen conditions, thus enhancing the survivability of the system and improving its life cycle. Moreover, enhancements too many pro ducts could provide better control by minimizing distortion and increasing precision. Another possible benefit is enhanced preventative maintenance of systems and thus better performance of their functions. By its nature, the technology of smart materials and structures is a highly interdisciplinary field, encompassing the basic sciences — physics, chemistry, mechanics, computing and electronics — as well as the applied sciences and engineering such as aeronautics and mechanical engineering. This may explain the slow progress of the application of smart structures in engineering systems, even if the science of smart materials is moving very fast.



7. STRUCTURAL APPLICATION OF SMART MATERIALS
The development of durable and cost effective high performance construction materials and systems is important for the economic well being of a country mainly because the cost of civil infrastructure constitutes a major portion of the national wealth. To address the problems of deteriorating civil infrastructure, research is very essential on smart materials. This paper highlights the use of smart materials for the optimal performance and safe design of buildings and other infrastructures particularly those under the threat of earthquake and other natural hazards. The peculiar properties of the shape memory alloys for smart structures render a promising area of research in this field.
7.1 MATERIALS AND APPLICATION
Shape Memory Alloys (SMA)
The term shape memory refers to the ability of certain alloys (Ni – Ti, Cu – Al – Zn etc.) to undergo large strains, while recovering their initial configuration at the end of the deformation process spontaneously or by heating without any residual deformation .The particular properties of SMA’s are strictly associated to a solid-solid phase transformation which can be thermal or stress induced. Currently, SMAs are mainly applied in medical sciences, electrical, aerospace and mechanical engineering and also can open new applications in civil engineering specifically in seismic protection of buildings.
Its properties which enable them for civil engineering application are
1. Repeated absorption of large amounts of strain energy under loading without permanent deformation. Possibility to obtain a wide range of cyclic behaviour –from supplemental and fully recentering to highly dissipating-by simply varying the number and/or the characteristics of SMA components.
2. Usable strain range of 70%
3. Extraordinary fatigue resistance under large strain cycles
4. Their great durability and reliability in the long run.
Structural Uses
1. Active control of structures
The concept of adaptive behavior has been an underlying theme of active control of structures which are subjected to earthquake and other environmental type of loads. The structure adapts its dynamic characteristics to meet the performance objectives at any instant. A futuristic smart bridge system (An artist rendition) is shown below :Fig.1 (3)
(Courtesy: USA Today dt. 03.03.97). Sun and Sun (6) used a thermo mechanical approach to develop a constitutive relation for bending of a composite beam with continuous SMA fibers embedded eccentric to neutral axis. The authors concluded that SMA’s can be successfully used for the active structural vibration control. Thompson et al (3) also conducted an analytical investigation on the use of SMA wires to dampen the dynamic response of a cantilever beam constrained by SMA wires.

Fig.1
2) Passive control of structures
Two families of passive seismic control devices exploiting the peculiar properties of SMA kernel components have been implemented and tested within the MANSIDE project and implimentation (Memory Alloys for New Seismic Isolation and Energy Dissipation Devices). They are Special braces for framed structures and isolation devices for buildings and bridges.
3) Smart Material Tag
These smart material tag can be used in composite structures. These tags can be monitored externally through out the life of the structure to relate the internal material condition. Such measurements as stress, moisture, voids, cracks and discontinuities may be interpreted via a remote sensor
4) Retrofitting
SMAs can use as self-stressing fibers and thus they can be applied for retrofitting. Self-stressing fibers are the ones in which reinforcement is placed into the composite in a non-stressed state. A prestressing force is introduced into the system without the use of large mechanical actuators, by providing SMAs. These materials do not need specialized electric equipments nor do they create safety problems in the field. Treatment can be applied at any time after hardening of the matrix instead of during its curing and hardening. Long or short term prestressing is introduced by triggering the change in SMAs shape using temperature or electricity.
5) Self-healing
Experimentally proved self-healing behavior which can be applied at a material micro level widens their spectrum of use. Here significant deformation beyond the first crack can be fully recovered and cracks can be fully closed.
6) Self-stressing for Active Control
Can be used with cementations fiber composites with some prestess, which impart self-stressing thus avoiding difficulties due to the provision of large actuators in active control which require continuous maintenance of mechanical parts and rapid movement which in turn created additional inertia forces. In addition to SMA’s some other materials such as polymers can also be temporarily frozen in a prestrained state that have a potential to be used for manufacturing of self-stressing cementitious composites .

7) Structural Health Monitoring
Use of piezo transducers, surface bonded to the structure or embedded in the walls of the structure can be used for structural health monitoring and local damage detection. Problems of vibration and UPV testing can be avoided here. Jones et. al., applied neural networks to find the magnitude and location of an impact on isotropic plates and experimented using an array of piezo-transducers surface bonded to the plate.

Substitute for steel?
It is reported that (4) the fatigue behaviour of CuZnAl-SMA’s is comparable with steel.If larger diameter rods can be manufactured. It has a potential for use in civil engineering applications. Use of Fibre reinforced plastics with SMA reinforcements requires future experimental investigations.
CARBON FIBRE REINFORCED CONCRETE(CFRC)
Its ability to conduct electricity and most importantly, capacity to change its conductivity with mechanical stress makes a promising material for smart structures .It is evolved as a part of DRC technology(Densified Reinforced Composites).The high density coupled with a choice of fibers ranging from stainless steel to chopped carbon and kelvar, applied under high pressure gives the product with outstanding qualities as per DRC technology. This technology makes it possible to produce surfaces with strength and durability superior to metals and plastics.
SMART CONCRETE
A mere addition of 0.5%specially treated carbon fibres enables the increase of electrical conductivity of concrete. Putting a load on this concrete reduces the effectiveness of the contact between each fibre and the surrounding matrix and thus slightly reduces its conductivity. On removing the load the concrete regains its original conductivity. Because of this peculiar property the product is called “Smart Concrete”. The concrete could serve both as a structural material as well as a sensor.
The smart concrete could function as a traffic-sensing recorder when used as road pavements. It has got higher potential and could be exploited to make concrete reflective to radio waves and thus suitable for use in electromagnetic shielding. The smart concrete can be used to lay smart highways to guide self steering cars which at present follow tracks of buried magnets. The strain sensitive concrete might even be used to detect earthquakes.
Active railway track support
Active control system for sleepers is adopted

to achieve speed improvements on existing bridges and to maintain the track in a straight and non-deformed configuration as the train passes With the help of optimal control methodology the train will pass the bridge with reduced track deflections and vibrations and thus velocity could be safely increased. Fig(3) shows various positions of the train with and without active railway track support.
Active structural control against wind
Aerodynamic control devices to mitigate the bi-directional wind induced vibrations in tall buildings are energy efficient, since the energy in the flow is used to produce the desired control forces. Aerodynamic flap system(AFS) is an active system driven by a feedback control algorithm based on information obtained from the vibration sensors(3).The area of flaps and angular amplitude of rotation are the principal design parameters. fig.(4) shows an active aerodynamic control device.










8. CONCLUSION

Today, the most promising technologies for lifetime efficiency and improved reliability include the use of smart materials and structures. Understanding and controlling the composition and microstructure of any new materials are the ultimate objectives of research in this field, and is crucial to the production of good smart materials. The insights gained by gathering data on the behaviors of a material’s crystal inner structure as it heats and cools, deforms and changes, will speed the development of new materials for use in different applications.

Structural ceramics, superconducting wires and nonstructural materials are good examples of the complex materials that will fashion nanotechnology. New or advanced materials to reduce weight, eliminate sound, reflect more light, and handle more heat will lead to smart structures and systems which will definitively enhance our quality of life. It has wide range of applications in various fields. This seminar and presentation deals with the smart materials and its applications.

REFERENCES


• Autumn 2000 _ Canadian Military Journal

• The AMPTIAC Quarterly, Volume 7, Number 2

• J.Holnicki-szulc and J.Rodellar(eds), Smart Structures.,3.High Technology-Vol.65


Reply
seminar class
Active In SP
**

Posts: 5,361
Joined: Feb 2011
#6
22-03-2011, 02:45 PM

presented by:
John Summerscales


.ppt   MATS324A14 smart.ppt (Size: 2.19 MB / Downloads: 286)
Smart materials
“smart responds to a stimulus with one predictable action”
l normal materials have limited responses
l smart materials have appropriate responses
l ... but response is the same every time
Smart materials
l smart materials have appropriate responses
 photochromic glass
• darkens in bright light
 low melting point wax in a fire sprinkler
• blocks the nozzle until it gets hot
 acoustic emission
• sounds emitted under high stress
 embedded optical fibres
• broken ends reflect light back
 microporous breathable fabrics
l Waterproof clothing
l Goretex®
l micro-porous expanded PTFE
discovered in 1969 by Bob Gore
l ~ 14 x 1012 micropores per m².
l each pore is about 700x larger than
a water vapour molecule
l water drop is 20,000x larger than a pore
Goretex:
Intelligent structures (IS)
“intelligent responds to a stimulus with a calculated response and different possible actions”
l composites made at low temp
l \ can embed additional components
l control can decide on novel response
Intelligent structures (IS)
l embed three elements of the system:
l sensors
signal processing and control
l actuators
l Sensors
l strain gauges
l microdieletric interdigitated sensors
l optical fibres
l piezoelectric crystals
l shape memory alloys
l electro-rheological fluids
l giant magnetoimpedance (GMI) wires
Signal processing
l issues with data fusion for large sensor arrays
Control
l proportional integral derivative (PID)
 proportional:
output = (gain x error) + bias
 integral:
output = gain x (error + ∫error w.r.t. time)
 derivative:
output = gain x derivative x de/dt
l advanced systems ...
Advanced control
l proportional integral derivative (PID)
l fuzzy logic control (FLC)
 sliding mode control
l artificial neural networks (ANN)
l genetic algorithms (GA)
l knowledge-based systems/
artificial intelligence/expert systems
Actuators
l hydraulic, pneumatic and electric
l piezoelectric crystals
 shape changes when voltage applied
l shape memory materials
 shape changes at a specific temperature
 alloys = SMA .... polymers = SMP
l magneto-rheological (MR) fluids
 viscosity changes with magnetic field
l electro-rheological (ER) fluids
Magneto-rheological (MR) fluids
Electro-rheological (ER) fluids
Intelligent Structures: applications

l artificial hand
 SMA fingers controlled by
nerve (myoelectric) signals
l vibration damping
 apply electric field to ER fluid
l skyscraper windows
 acoustic emission warning system
Biomimetics
l a.k.a bionics, biognosis
l the concept of taking ideas from nature to implement in another technology
 Chinese silk cultivation begins c.4000BC
• Colin Thubron, Shadow of the Silk Road, Chatto & Windus, 2006.
 Daedalus' wings - early design failures
l gathering momentum due to the
ever increasing need for
sympathetic technology
Biomimetics
l “inspiration rather than imitation”
Janine Benyus.
l “design inspired by nature”
BioNIS thematic network
Biomimetics
l Notable innovations from understanding nature
 Velcro
 Gecko tape
 Lotus effect self-cleaning surfaces
 Drag reduction by shark skin
 Platelet TechnologyTM for pipe repair
 Smart-fabric
 ElekTex™
Biomimetics
l Velcro
 small hooks enable seed-bearing burr
to cling to tiny loops in fabric
Gecko tape
l Inspiration from the remarkable hairs that allow geckos to hang single-toed from sheer walls and walk along ceilings
l researchers at the University of California - Berkeley, created an array of synthetic micro-fibres that uses very high friction
to support loads on smooth surfaces.
l Biomimetics: Lotus effect
l most efficient self-cleaning plant
= great sacred lotus
(Nelumbo nucifera)
l mimicked in paints and
other surface coatings
l pipe cleaning in oil refineries (Norway)
Biomimetics
l Lotus effect self-cleaning surfaces
l surface of leaf water droplet on leaf
l Image from library.thinkquest27468/e/lotus.htm
l drag reduction by shark skin
 special alignment and grooved structure
of tooth-like scales embedded in shark skin
decrease drag and thus
greatly increase swimming proficiency
 Airbus fuel consumption down 1½%
when “shark skin” coating applied to aircraft
Platelet TechnologyTM
l Brinker Technology Platelet TechnologyTM
l discrete particles released into pressurised pipe flow
l when particles encounter modified flow at a leak, fluid forces entrain them into the leak and hold them against the pipe wall
l seals and marks the position of the leak for subsequent detection.
l brinker-technology.com animation and video links now dead L
Smart-fabric
l pine-cone model
l adapts to changing temperatures
by opening when warm or shutting tight if cold
ElekTex™
l looks and feels like a fabric
l capable of electronic x-y-z sensing
l fold it, scrunch it or wrap it
l lightweight, durable, flexible
l cost competitive
l cloth keyboards and keypads
Reply
rockisshell
Active In SP
**

Posts: 2
Joined: Apr 2011
#7
09-04-2011, 05:01 PM

I see the thread and it is a nice details given about the material and I am really longing for this types of the things. I hope this one is a benefit to other also .
Reply
nithinprakas
Active In SP
**

Posts: 2
Joined: Jun 2011
#8
12-06-2011, 08:29 PM

halooo,sir plz send me more details about Smart Materials
Reply
nithinprakas
Active In SP
**

Posts: 2
Joined: Jun 2011
#9
05-07-2011, 08:49 PM

can u plz add a presentation file on "SMART MATERIALS"
Reply
seminar ideas
Super Moderator
******

Posts: 10,003
Joined: Apr 2012
#10
28-06-2012, 05:16 PM

smart materials


.doc   smart materials in automobile seminar.doc (Size: 1.3 MB / Downloads: 46)

INTRODUCTION

Science and technology have made amazing developments in the design of electronics and machinery using standard materials, which do not have particularly special properties (i.e. steel, aluminum, gold). Imagine the range of possibilities, which exist for special materials that have properties scientists can manipulate. Some such materials have the ability to change shape or size simply by adding a little bit of heat, or to change from a liquid to a solid almost instantly when near a magnet; these materials are called smart materials. What are they? They are those materials that posses both intrinsic and extrinsic capabilities to respond to stimuli and environmental changes. They respond to changes in temperature, moisture, pH, magnetic Field, electric field, etc. The term “smart materials” encompasses a wide variety of materials, such as piezoelectric materials, magneto-rheostatic materials (MR), electro-rheostatic materials (ER), and shape memory alloys etc.
Like many scientific advances, smart fluids were discovered by accident. Researchers’ using marble and oil to construct a very high voltage switch in 1940’s noticed that as the switch operated, the marble eroded into a dust in the oil, which turns into from a liquid to a paste in the presence of high voltage. After the initial novelty wore off, interest in smart fluids languished through the 1970’s and 1980’s.
Such controllable fluids and materials whose rheology may vary by the application of the external inputs have long been seen as offering the possibility simple quite rapid response interfaces between electronic controls and mechanical systems. The automotive and aerospace industries were probably the first to identify the potential engineering application of smart fluids and material – Notably for vibration control, variable torque transmission, medical rehabilitation, and Chromogenic application. Nowadays, many additional avenues are been explored, e.g., civil engineering structures,Robotics and manufacturing and distributed structures.[1]


LITERATURE REVIEW

The first observation of the shape memory effect in materials occurred in the 1930's. A Swedish physicist by the name of Arne Olander discovered an interesting phenomenon when working with an alloy of gold (Au) and cadmium (Cd). The Au- Cd alloy was plastically deformed when cool and upon heating it returned to original or ‘memorized’ dimensional configuration. This phenomenon was called the Shape Memory Effect (SME) and the alloys that exhibited this behavior were called Shape Memory Alloys (SMA). At this time however, there were few, if any, practical uses of this type of alloys, until 1958, when researchers Chang and Read demonstrated the Shape Memory Effect at the Brussels World’s Fair. They showed that the SME could be used to perform mechanical work by cyclically lifting a weight using an Au-Cd SMA
Further research revealed other materials that also demonstrated this phenomenon. In 1962 the shape memory properties of Nickel Titanium alloys were discovered by accident at the US Naval Ordnance Laboratories. Although pure Nickel Titanium has very low ductility in the martensitic phase, the properties can be much modified by the addition of a small amount of a third element. This group of alloys is now known as Nitinol™ (Nickel-Titanium-Naval-Ordnance-Laboratories). NiTi SMAs proved to be less expensive, easier to work with and less dangerous from a health standpoint than previously discovered alloys. These factors led to a renewed interest in SMAs and their application. Companies recognized the potential of using the SME in engineering applications. As a result, starting in the 1970’s commercial products began to appear. The first commercial applications for this new material were static devices, like pipefittings. These fittings were applied first by the U.S. Air Force and later also the Navy used them for original equipment production and tube system. Also in the early 1970's a group of Brass (CuZnAl) alloys were discovered to exhibit shape memory properties. Although they were cheaper than Nitinol™ and able to perform at wider temperature ranges, they also has some disadvantages like lower work output and unwanted ageing, which made them less interesting for high power applications. Following these static applications, researchers began to propose SMA devices to perform dynamic tasks. The SMA devices began to play the role of sensors and actuators. In order to perform a dynamic task, the SMA must experience a cycle of heating, cooling, and deformation. As an example of this actuators were used in temperature regulation systems, in which the environmental temperature could be
used for thermal actuation of the SMA.
Recent research has focused on the improvement of Nitinol™ properties, especially to make it suitable for a wider range of temperatures. Also research concerning the application and control of SMA actuators in robotic systems has been conducted and expanded through the present.[1]

AN A-TO-Z GUIDE TO SMART MATERIALS

Smart Materials: Emerging Markets for Intelligent Gels, Ceramics, Alloys, and Polymers is your guide to the world of smart materials. In one handy volume it will give you a hard-headed assessment of new applications and markets ... And brief you on important developments related to dozens of materials in a wide range of categories, including:

Piezoelectric materials:
These ceramics or polymers are characterized by a swift, linear shape change in response to an electric field. The electricity makes the material expand or contract almost instantly. The materials have potential uses in actuators that control chatter in precision machine tools, improved robotic parts that move faster and with greater accuracy, smaller microelectronic circuits in machines ranging from computers to photolithography printers, and health-monitoring fibers for bridges, buildings, and wood utility poles. [2]
Reply

Important Note..!

If you are not satisfied with above reply ,..Please

ASK HERE

So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page

Quick Reply
Message
Type your reply to this message here.


Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  Smart materials in Automobile seminar ideas 8 10,043 25-10-2013, 11:46 AM
Last Post: Kesava17
  Full Report on Smart materials in Automobile study tips 0 688 06-06-2013, 04:52 PM
Last Post: study tips
  INTRODUCTION TO SMART MATERIALS PPT study tips 0 825 30-05-2013, 12:04 PM
Last Post: study tips
  Composite materials on aerospace application PPT study tips 0 829 02-05-2013, 12:41 PM
Last Post: study tips
  ppt on Engineering materials study tips 0 775 19-02-2013, 10:10 AM
Last Post: study tips
  Universal testing machine for mechanical properties of thin materials pdf study tips 0 806 18-02-2013, 09:55 AM
Last Post: study tips
  HEAT CAPACITIES OF DIFFERENT MATERIALS ppt project girl 0 370 02-02-2013, 02:18 PM
Last Post: project girl
  Composite –Materials, Manufacturing, and Mechanics (An Introduction) project girl 0 396 02-02-2013, 11:44 AM
Last Post: project girl
  Smart Grid, Smart City presentation project girl 0 382 01-02-2013, 02:18 PM
Last Post: project girl
  SELF HEALING MATERIALS AND APPLICATIONS seminar tips 0 442 29-01-2013, 02:48 PM
Last Post: seminar tips