smart materials

SMART MATERIALS: -what smart materials are; -types of smart materials; -examples and application.

SMART MATERIALS

Electroactive Polymer

Smart concrete

Smart materials (responsive materials) are materials that are manipulated to respond in a controllable and reversible way, modifying some of their properties by mechanical stress or by temperature.

Piezoeletrics

Magnetostrictive

Some examples of smart materials:

• Piezoelectrics
• Shape Memory Alloys
• Magnetostrictive
• Hydrogels
• Electroactive Polymer
• Smart concrete

Shape Memory Alloys

Hydrogels

SMART CONCRETE

Smart concrete is capable of sensing very small structural mistakes and so finds application in checking the internal condition of structures, particularly after an earthquake. One factor that may contribute to the global smart concrete market is the widespread use of concrete as a composite material and its inability to withstand tension.

USE OF SMART CONCRETE

Smart concrete has not made it to market yet . Possible uses of smart concrete include: building security. In addition, smart concrete is expected to be used for building facility management. to weigh each room of a building to monitor the room occupancy in real time.

Piezoeletric

Piezoelectricity is the electric charge that accumulates in certain solid materials such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins in response to applied mechanical stress. Piezoeletric converts electrical energy to mechanical energy.

The word piezoelectric originates from the Greek word piezein, which literally means to squeeze or press. Instead of squeezing grapes to make wine, we’re squeezing crystals to make an electric current! Piezoelectricity is found in a ton of everyday electronic devices for example speakers and microphones. So: Piezoelectricity is the process of using crystals to convert mechanical energy into electrical energy, or vice versa.

How it works in a crystal

SHAPE MEMORY ALLOYS (SMA)

Shape Memory Alloys

A shape-memory alloy is an alloy that can be deformed when cold but returns to its original shape when heated. SMA’s have the ability to change phase as a function of temperature, and in that process generate a force or motion. They are capable of relatively high energy but move slowly. They may also be called memory metal. Parts made of shape-memory alloys can be hydraulic, pneumatic, and motor-based systems. They can also be used to make hermetic joints in metal tubing.

Use of SMA

The most commonly available Shape Memory Alloy is Nitinol. SMA’s have the ability to change phase as a function of temperature, and in that process generate a force or motion. They are capable of relatively high energy but move slowly. Typically applications include morphing structures, thermal triggers, and some high strain energy absorbing applications. Advanced materials still under development include magnetically activated shape memory alloys.

ELECTROACTIVE POLYMER (EAP)

Electroactive Polymers (EAPs) are polymers that change their size, shape or volume in response to a strong electrical field. In the field of “active materials” electroactive polymers stand out due to their large active deformation potential, high response speed, low density and improved resilience. They are extremely lightweight, inexpensive, fracture tolerant and compliant

Use of EAP

They can be used as mechanical actuators they can also perform as sensors. Secondly they can be used to convert mechanical work into electrical energy and as such be applied as generators, with their softness and flexibility in shape and design providing additional qualities.Other types of electronic EAPs include ferroelectric polymers, electrostrictive graft polymers, electrostrictive paper, piezoelectric polymers and liquid crystal elastomers. The shape flexibility of electroactive polymers makes them very versatile materials. They have been utilized as artificial muscles, both for prosthetic purposes or “super-human” exoskeletons. For architectural applications and scale the material exhibits very promising properties, especially its homogeneous surface qualities, transparency and large active deformation are visually astonishing.

MAGNETOSTRICTIVE

Magnetostriction is the physical phenomenon that consists in the variation in length of a material, always metallic. The variation is determined by different variables such as temperature, mechanical and physical treatments. This effect is due to the microscopic reorientation of the atomic dipoles

HYDROGELS

A hydrogel is a hydrophilic polymer that does not dissolve in water and they can absorb and hold water, or other liquids, under certain environmental conditions. They are highly absorbent . These properties are used in the biomedical area. Many hydrogels are synthetic, but some are derived from nature. They can also chemically to respond to different stimuli.

Use of magnetostrictive

Magnetostrictive is used for the sound propagation, some examples are high force linear motors, control systems, medical and industrial things and for war sonar

HYDROGELS

USE OF HYDROGELS

There are different primary areas where hydrogels are used quite commonly. Not only it can help produce contact lenses for people that need glasses, it can also be used as a hygiene product and is the perfect complement to dressing wounds. It has many commercial uses. For example, in the industry of tissue engineering. However, it is the very high cost of producing hydrogels which has limited its expansion into other markets.