Smart+Materials+-+A+Defiance+Of+Physics+-+Hesham+Barakat


 * =__What Are Smart Materials?__=

A smart fluid developed in labs at the Michigan Institute of Technology || I look like a pen is
 * Smart materials** are materials that have one or more properties that can be significantly changed by external factors, such as [|stress], [|temperature], moisture, [|pH], [|electric] or [|magnetic] fields.
 * [[image:http://webdocs.cs.ualberta.ca/%7Edatabase/MEMS/sma_mems/img/goop.gif width="299" height="239"]]

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.

Smart materials have properties that can be dramatically changed. Most everyday materials have physical properties, which cannot be significantly altered; for example if oil is heated it will become a little thinner, whereas a smart material with variable may turn from a fluid which flows easily to a solid. A variety of smart materials already exist, and are being researched extensively. These include piezoelectric materials, magneto-rheostatic materials, electro-rheostatic materials, and shape memory alloys. Some everyday items are already incorporating smart materials (coffeepots, cars, the International Space Station, eyeglasses) and the number of applications for them is growing steadily. || Each individual type of smart material has a different property which can be significantly altered, such as viscosity, volume, and conductivity. The property that can be altered influences what types of applications the smart material can be used for.

__**There are a number of types of smart material, some of which are already common. Some examples are as following**__**:** Piezoelectric materials have two unique properties which are interrelated. When a piezoelectric material is deformed, it gives off a small electrical discharge. Alternately, when an electrical current is passed through a piezoelectric material it experiences a significant increase in size (up to a 4% change in volume)
 * =I. Piezoelectric Materials=

Piezoelectric materials are most widely used as sensors in different environments. They are often used to measure fluid compositions, fluid density, fluid viscosity, or the force of an impact. An example of a piezoelectric material in everyday life is the airbag sensor in your car. The material senses the force of an impact on the car and sends and electric charge deploying the airbag. media type="youtube" key="s3Ftl6n9Oq0" height="251" width="475"

An illustration of the Piezoelectric Effect


 * =II. Electro-rheostatic and Magneto-rheostatic=
 * Electro-rheostatic (ER) and magneto-rheostatic (MR) materials are fluids, which can experience a dramatic change in their viscosity. These fluids can change from a thick fluid (similar to motor oil) to nearly a solid substance within the span of a millisecond when exposed to a magnetic or electric field; the effect can be completely reversed just as quickly when the field is removed. MR fluids experience a viscosity change when exposed to a magnetic field, while ER fluids experience similar changes in an electric field. The composition of each type of smart fluid varies widely. The most common form of MR fluid consists of tiny iron particles suspended in oil, while ER fluids can be as simple as milk chocolate or cornstarch and oil.

MR fluids are being developed for use in car shocks, damping washing machine vibration, prosthetic limbs, exercise equipment, and surface polishing of machine parts. ER fluids have mainly been developed for use in clutches and valves, as well as engine mounts designed to reduce noise and vibration in vehicles. media type="youtube" key="SBXQ-6uI8GY" height="315" width="560" || The MR fluid is liquid as shown on the left, when no magenetic field is present, but turns solid immediately after being placed in a magnetic field on the right. ||

> A **shape-memory alloy** (**SMA**, **smart metal**, **memory metal**, **memory alloy**, **muscle wire**, **smart alloy**) is an [|alloy] that "remembers" its original, cold-forged [|shape]: returning the pre-deformed shape by heating. This material is a lightweight, solid-state alternative to conventional actuators such as hydraulic, pneumatic, and motor-based systems. Shape-memory alloys have applications in industries including medical and aerospace.
 * =III. Shape Memory Alloys=

Applications:
[|Boeing], [|General Electric Aircraft Engines], [|Goodrich Corporation], [|NASA], and [|All Nippon Airways] developed the Variable Geometry Chevron using shape-memory alloy that reduces aircraft's engine noise
 * 1) ==== Aircraft ====

2.Piping The first consumer commercial application for the material was as a [|shape-memory coupling] for piping, e.g. oil line pipes for industrial applications, water pipes and similar types of piping for consumer/commercial applications.

Nitinol alloys exhibit two closely related and unique properties: [|shape memory] and [|superelasticity] (also called [|pseudoelasticity]). Shape memory refers to the ability of nitinol to undergo deformation at one temperature, then recover its original, undeformed shape upon heating above its "transformation te media type="youtube" key="Y7jjqXh7bB4" height="250" width="336" align="right" mperature". Superelasticity occurs at a narrow temperature range just above its transformation temperature; in this case, no heating is necessary to cause the undeformed shape to recover, and the material exhibits enormous elasticity, some 10-30 times that of ordinary metal. The term nitinol is derived from its composition and its place of discovery: (**Nickel Titanium Naval** There are four commonly used types of applications for nitinol.
 * NitiNOL:**
 * Nickel titanium**, also known as **nitinol**, is a [|metal] [|alloy] of [|nickel] and [|titanium], where the two elements are present in roughly equal atomic percentages.
 * Ordnance Laboratory**).
 * Free Recovery: nitinol is deformed at a low temperature, and heated to recover its original shape.
 * Constrained Recovery: The same, except that recovery is rigidly prevented, and thus a stress is generated.
 * Work Production: Here the alloy is allowed to recover, but to do so it must act against a force (thus doing work).
 * Superelasticity: the nitinol acts as a super spring.

PVDF is a specialty plastic material in the fluoropolymer family; it is used generally in applications requiring the highest purity, strength, and resistance to solvents, acids, bases and heat and low smoke generation during a fire event. Compared to other fluoropolymers, it has an easier melt process because of its relatively low melting point of around 177 °C. It has a low density (1.78) and low cost compared to the other fluoropolymers. It is available as piping products, sheet, tubing, films, plate and an insulator for premium wire. It can be injected, molded or welded and is commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium ion batteries. It is also available as a crosslinked closed cell foam, used increasingly in aviation and aerospace applications. A fine powder grade, KYNAR 500 PVDF or HYLAR 5000 PVDF, is also used as the principal ingredient of high-end paints for metals. These PVDF paints have extremely good gloss and color retention, and they are in use on many prominent buildings around the world, e.g. the [|Petronas Towers] in Malaysia and [|Taipei 101] in Taiwan, as well as on commercial and residential metal roofing.
 * ==PVDF==
 * Polyvinylidene fluoride**, or **PVDF** is a highly non-reactive and pure [|thermoplastic] [|fluoropolymer].


 * Aircraft maneuverability depends heavily on the movement of flaps found at the rear or trailing edge of the wings. The efficiency and reliability of operating these flaps is of critical importance.

Most aircraft in the air today operate these flaps using extensive hydraulic systems. These hydraulic systems utilize large centralized pumps to maintain pressure, and hydraulic lines to distribute the pressure to the flap actuators. In order to maintain reliability of operation, multiple hydraulic lines must be run to each set of flaps. This complex system of pumps and lines is often relatively difficult and costly to maintain.

Many alternatives to the hydraulic systems are being explored by the aerospace industry. Among the most promising alternatives are piezoelectric fibers, electrostrictive ceramics, and shape memory alloys.

media type="youtube" key="R6qHY1H6piE" height="315" width="560" align="center"


 * __**Refrences :**__

> > > P.S. : This is a reorganized "copy-paste" report, added info from numerous references , and illustrative videos added too from Youtube.
 * 1) http://en.wikipedia.org/wiki/Smart_material
 * 2) http://en.wikipedia.org/wiki/Nickel_titanium
 * 3) http://webdocs.cs.ualberta.ca/~database/MEMS/sma_mems/smrt.html
 * 4) Youtube
 * 5) Google Image Search
 * 6) http://www.piezo.com/