Smart Materials😎

6 min readMay 25, 2021

What are Smart Materials?

Smart Materials are designed materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli such as stress, temperature, moisture pH, electric or magnetic field.

Smart materials are also called responsive or active materials.

Types of Smart Materials :

1.Piezoelectric Smart Materials : Produces voltage when stress is applied. The structures made from these materials can bend, expand or contract when a voltage is applied. Actually the internal molecular structure of piezoelectric materials produces coupling between the mechanical stress and the applied electric field.

2.Shape Memory Alloy : These materials have a tendency to retain their originality when subjected to external stimuli. These materials exist in two phases named ‘Martensite’ and ‘ Austenite’. The shape changes occur between these two phases.

Shape Memory Alloys(SMA) can be actuated by stress, temperature, or presence of magnetic field as well.

When we heat them above their transformation temperature these materials become deformed, but these materials regain their shape as they cool down. nickel-titanium or Nitinol is a famous alloy that is most widely used nowadays.

3.Thermo-responsive Materials : As the name suggests, These materials have the ability to hold different shapes at different temperatures.

4.PH Sensitive Materials : These materials have properties to change their color when there is change in the acidity of the liquid.

5.Magneto-rheostatic fluid : These materials the oil will solidify when brought into the magnetic field. The solidification of the liquid is so strong that it can lift 100kgs without any problem.

6.Rheological-Materials: These materials are in liquid phase which can change their state instantly through the applications of an electric or magnetic charge. These fluids are generally used in brakes, shock absorbers and dampers for vehicle seats.

7.Electrochromic Materials: Electrochromic is an ability of materials to changes its optical properties (eg. color) when voltage is applied across it.

Image From(Nanostructured electrochromic smart windows: traditional materials and NIR-selective plasmonic nanocrystals).

8.Smart Gels: These are the gels that can shrink or swell by several orders of magnitude. Some of them can also be programmed to absorb or release fluids in responses to chemical or physical stimuli. These gels are also be used in areas like food, drug delivery, organ replacement and chemical processing.

Applications of Smart Materials :

Aeronautics : In aircraft or automotive structure to reduce the vibrations Piezoelectric actuators were used. Later in aircraft shape memory alloy was used to control the spatial goal i.e. the structure of aircraft 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 decrease the breaking stresses of the blades to remove vibration and noise.
Nuclear industries : Smart materials offer a great range of applications to the nuclear field from enhancing safety measures to the personal exposure reduction, life-cycle cost reduction and performance improvement.
Civil Engineering : Smart Materials are able to detect the cracks in concrete structure, vibration of tall buildings, to predict the choc waves in the concrete and metallic structure, and can analyze innovative seismic retrofit of buildings and bridges.
Reducing Waste : In a present scenario electronic and non-disposable waste is increasing day by day all over the world. The radiation from this is also hazardous for human beings and should be removed first. In this situation smart materials can help to automate this process. Manufacturing of fasteners constructed from shape memory alloys are used that can self-release on heating. Once these fasteners are formed then the hazardous and recyclable waste can easily be separable. Using these fasteners of different temperatures, products could be disassembled hierarchically so that materials can be sorted automatically.
Electrochromic materials are used in LCDs and cathodes in lithium batteries.
Two main applications of smart gels are in artificial muscle fabrication and drug release systems. In the drug release system also a smart gel containing the desired water soluble drug is injected into the patient.
In lighters or portable speakers with a piezo fuse a sudden and strong pressure is used to produce a voltage. The spark then ignites the gas.

Examples of Smart Materials :

Graphene : Graphene has higher Thermal and electrical conductivity than copper and silver has properties like ionising radiation.

Image From(Graphene: the “miracle material” that will change the world)

XPL : It is a silicone-based polymer that stick to the dermis like a second skin.
Shrilk : The main component used is chitin and carbohydrates found in krill shells. It can be used to imitate plant growth.
Hydrogels: Hydrogels can be adjusted to absorb and hold water, or other liquids, under different environmental conditions.

Image From(Nanoscience and smart materials)

Future Scope

In Nanotechnology to Revolutionize Smart Materials Technology

In today’s world nanotechnology is set to accelerate development of improved and complex smart material technologies. Researchers nowadays are considering the different possibilities of designing, altering, and controlling material structure at very low levels (Nano) in order to improve material performance and process efficiency. Further Steps in nanomaterials are expected to increase product quality and performance, and they are finding acceptance in different applications such as sensors and electronic devices. Nano sensor particles help in developing tools for detecting living cells and serve as reporters in industrial process monitoring. In the upcoming days, smart materials are expected to derive their success from nanotechnology that is used to be instrumental in creating more varied, composite, and intelligent systems.

Smart Materials Expected to Cater to Diverse Applications

Advancement in smart materials allow them to cater a different set of applications, in the fields like defense, aerospace, healthcare, electronics, and semiconductor industries. Although very few applications right now available are commercially viable and also their potential for future acceptance is irrefutable. The digital industry is also adopting smart materials for read/write head micropositioners and upcoming data storage devices. Researchers are also developing piezo-accelerometers which anticipate and correct head-motion-related read/write errors. In the healthcare market field also, smart material technologies are making their way into several analytical devices for detecting and diagnosing composite medical conditions. In future , smart materials are also to be useful for fabricating insulin pumps and drug delivery devices.

References

Blog Written By: Ritesh Thakur, Vishal Thoke, Utsav Patel, Sushant Vaidkar, Vedant Valsangkar.