Smart() materials

Smart() materials

    Tab  Yahoo  - , , Hits: 857

Smart() materials

Smart() materials

Smart materials are materials that have one or more properties that can be significantly () changed in a controlled fashion by external stimuli (), such as stress(), tempera 949b13ej ture, moisture(), pH, electric or magnetic fields. There are a number of types of smart material, some of which are already common. Some examples are as following:

        Piezoelectric materials are materials that produce a voltage when stress is applied. Since this effect also applies in the reverse manner( ), a voltage across(, ) the sample (,) will produce stress within the sample. Suitably () designed structures made from these materials can therefore be made that bend(), expand() or contract() when a voltage is applied.

        Shape() memory alloys() and shape memory polymers are Thermoresponsive materials where deformation can be induced and recovered through temperature changes.

        Magnetic shape memory alloys are materials that change their shape in response to a significant change in the magnetic field.

        pH-sensitive polymers are materials which swell/collapse when the pH of the surrounding media changes.

        Temperature-responsive polymers are materials which undergo() changes upon temperature.

        Halochromic() materials are commonly materials that change their colour as a result of changing acidity(). One suggested() application() is for paints that can change colour to indicate corrosion in the metal underneath them. Chromogenic systems change colour in response to electrical, optical or thermal changes. These include electrochromic materials, which change their colour or opacity() on the application of a voltage (e.g. liquid crystal displays), thermochromic materials change in color depending() on their temperature, and photochromic materials, which change colour in response to light - for example, light sensitive sunglasses that darken when exposed to bright sunlight. Non-Newtonian fluid() is a liquid() which changes its viscosity in response to an applied shear rate. In other words the liquid will change its viscosity in response to some sort of force() or pressure(). One good example of this is Oobleck, a fluid that seems to temporarily turn into a solid() when a force is applied quickly.[1] Another good example is Custard, as long as it is starch based.

  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.

Smart materials have one or more properties that can be dramatically() altered(). 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 viscosity 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.

Most everyday materials have physical properties, which cannot be significantly() altered. Smart materials are materials that can be dramatically () changed by external stimuli (), such as stress(), tempera 949b13ej ture or electric or magnetic fields.

There are a lot of such materials already exist: There are piezoelectric materials, that can produce electricy when stress is applied, there are Shape() memory alloys or magnetic Shape() memory alloys that can change their turnover(), there are Temperature-responsive polymers and many many othe.

I think that smart materials is a part of our every day life. They maintenance in many different thinks. That is all.