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Smart materials

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smart materials

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Smart materials

  1. 1. Smart Materials
  2. 2. 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 fields.
  3. 3. TYPES OF SMART MATERIALS There are a number of types of smart material, some of which are already common. Some examples are as following: • Piezoelectric materials • Shape-memory alloys • Photomechanical materials • Self-healing materials • Thermoelectric material
  4. 4. Piezoelectric MATERIALS • 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. • Piezoelectricity is found in useful applications such as the production and detection of sound, generation of high voltages, electronic frequency generation, microbalances,., and everyday uses such as acting as the ignition source for cigarette lighters and push-start propane barbecues.
  5. 5. Shape-memory polymer • Shape-memory polymers (SMPs) are polymeric smart materials that have the ability to return from a deformed state (temporary shape) to their original (permanent) shape induced by an external stimulus (trigger), such as temperature change. • One of the first conceived industrial applications was in robotics where shape- memory (SM) foams were used to provide initial soft pretension in gripping. the materials have seen widespread usage in e.g. the building industry (foam which expands with warmth to seal window frames), sports wear (helmets, judo and karate suits) and in some cases with thermochromic additives for ease of thermal profile observation.Polyurethane SMPs are also applied as an autochoke element for engines. • In medicine it is used in orthopedic surgery
  6. 6. Photomechanical materials • The photomechanical effect is the change in the shape of a material when it is exposed to light. More recently, Uchino demonstrated that a photostrictive material could be used as legs in the construction of a miniature optically-powered "walker." • The most common mechanism of the photomechanical effect is light-induced heating.
  7. 7. Self-healing material • Self-healing materials have the intrinsic ability to repair damage due to normal usage, thus expanding the material's lifetime • Rothwell’s Best-of-the-Best winner proposes new kind of glass that is not only environmentally friendly and biocompatible, but is also self- healing. The idea combines chitosan and oxetane compounds into a bioactive glass
  8. 8. Thermoelectric materials • Thermoelectric materials are used to build devices that convert temperature differences into electricity and vice- versa.

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