Smart Materials -Types Properties & Application

In the manufacturing world now we need some ‘Intelligent’ or Smart materials which can change their property according to our requirement.

 Smart Materials

The materials which are designed materials that have more than one properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, pH, electric or magnetic fields are called smart materials.

Various types of smart materials are being used now a day those hold all the physical and chemical abilities and changes their properties according to the environment and need at that situation.

Types & properties of Smart Material

1) Shape memory material or Alloy

    It is very common example of Smart material. Basically these type of smart material has tendency to retain its original when subjected to external stimuli i.e. stress. These shape changes occurs between two phase martensite to austenite. Martensite phase is stable at lower temperature and austenite phase is stable at higher temperature. Basically these material exist between two phase. Because of these excellent mechanical properties the application of these materials has been increasing day by day such as in the field of automotive, aerospace, mini actuators and micro electromechanical systems and biomedical.

2) Microvascular materials

   This materials contains a vascular network for the storage and transport of functional fluids within a host material. When a failure occurs, the pressure is released at one end of the tube causing the healing agent to pump in to the place where it's needed

3) Self healing materials

   We can say the materials which respond to the damage by automatically applying some repairing mechanism. Several SH mechanisms have been proposed or demonstrated. The first self-healing materials are polymers it comes with internal embedded adhesive.

4) Piezoelectric materials

    This materials has tendency to produce voltage when stress is applied and same process can happens in a reversible manner. The structure made with this material can bend, expand and compress. It have Very high frequency response and are Self generating, so no need of external source. But It is not suitable for measurement in static condition.

5) Thermo-responsive Materials

    This materials have ability to hold different shapes at different temperature.

6) Magneto-restrictive Materials

    The materials that can alter their shape when subjected to magnetic field. This is reversible process so when magnetic field will be applied then change in shape will occur. These materials are almost similar to the piezoelectric materials difference is only that they respond to electric field while magneto-restrictive material has tendency to response to the magnetic field.

7) Electrostrictive materials

    These material as the same properties as piezoelectric material,The materials that can alter their shape when subjected to Electric field.

8) Photomechanical materials

    Basically photostrictive materials which undergo a very small deformation under the effect of light photons and used to make a walking device that is powered by modulated light.

9) Chromic Materials

 Chromic Materials are The materials which have very excellent property to change their color when subjected to external impetus like  temperature, lights, electric field. These materials can more classified into 

• Thermochromic materials 
• Photo chromic materials 
• Halo chromic materials

10) pH sensitive materials

   pH sensitive materials are The materials which have properties to change their color when their will be the change in the acidity of the liquid. These kind of smart materials can be use to indicates the corrosion by mixing it with the paint.

Application Of Smart Materials

 Nowadays, the new technologies is taking great interest in the Smart materials to make it more applicable in commercial, production and many other field.

1) In Aeronautics Field

    The Smart material plays a great role in the field of aeronautics. In aircraft or automotive structure to reduce the vibrations we use Piezoelectric actuators. Later in aircrafts we used shape memory alloy to control the spatial goal i.e the structure of aircrafts during the deformations, checking the upper and lower surface of the wings to increase the lift or decrease the drag, to reduce shock waves, to reduce the breaking stresses of the blades to reduce vibration and noise.

2) Defense and Space

    Smart materials have developed techniques to control vibrations and change shape in helicopter rotor blades. Shape-memory-alloy devices are also being developed that are capable of achieving accelerated breakup of vortex waves of submarines and similarly different adaptive control surfaces are developed for airplane wings.

3) Nuclear Industries

    Smart material technology offers new opportunities in nuclear industrial sector for safety enhancement, personal exposure reduction, life-cycle cost reduction and performance improvement. However, the radiation environments connected with nuclear operations represent a unique challenge to the testing, qualification and use of smart materials. However, the use of smart materials in nuclear facilities requires a great knowledge about the materials respond to irradiation and how this response is influenced by the radiation dose.

4) Health Monitoring

    The embedding smart sensors within the structure to monitor the damage and stress and can reduce the repairing cost and can increase their life. This smart health monitoring of structure is using over forty bridges worldwide.

5) Reducing Waste

    Nowadays, Electronic and non-disposable waste is increasing day by day in all over the world. Electronic waste is fastest growing waste in the world and becoming a great problem for the human world. During disposal and processing of such wastes, hazardous and recyclable materials should be removed first. Recently fasteners constructed from shape memory materials are used that can self release on heating. Once the fasteners have been released, components can be separated simply by shaking the product. By using fasteners that react to different temperatures, products could be disassembled hierarchically so that materials can be sorted automatically. 

6) Medical field

    In the field of medical science and biomedical lots of research I still going on for the better results. Now a days, for artificial muscle application, polyelectrolyte gels are being experimented, in whicha polymer matrix swollen with a solvent that can expand or contract when exposed to an electric field. Moreover the robot doctors for the surgery is not the new for this field.

Conclusion

    The smart materials are being used now a day for the different purpose and the researched are also going on for further improvement in smart materials. The technology of smart materials interdisciplinary field. Starting with the basic sciences such as physics, chemistry, mechanics, computing and electronics it also covers the applied sciences and engineering such as aeronautics and mechanical engineering.