smart material

{{Short description|Material that can be externally controlled}}

{{More citations needed|date=November 2013}}

Smart materials, also called intelligent or responsive materials,{{cite book |last1=Bengisu |first1=Murat |last2=Ferrara |first2=Marinella |title=Materials that move : smart materials, intelligent design |date=2018 |publisher=Springer International Publishing |isbn=9783319768885}}{{Page needed|date=July 2020}} are designed materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, moisture, electric or magnetic fields, light, temperature, pH, or chemical compounds.{{Cite journal |last=Brizzi |first=Silvia |last2=Cavozzi |first2=Cristian |last3=Storti |first3=Fabrizio |date=2023-09-29 |title=Smart materials for experimental tectonics: Viscous behavior of magnetorheological silicones |url=https://www.sciencedirect.com/science/article/pii/S0040195123003360 |journal=Tectonophysics |pages=230038 |doi=10.1016/j.tecto.2023.230038 |issn=0040-1951}}{{Cite journal |last=Bahl |first=Shashi |last2=Nagar |first2=Himanshu |last3=Singh |first3=Inderpreet |last4=Sehgal |first4=Shankar |date=2020-01-01 |title=Smart materials types, properties and applications: A review |url=https://www.sciencedirect.com/science/article/pii/S2214785320331278 |journal=Materials Today: Proceedings |series=International Conference on Aspects of Materials Science and Engineering |volume=28 |pages=1302–1306 |doi=10.1016/j.matpr.2020.04.505 |issn=2214-7853}} Smart materials are the basis of many applications, including sensors and actuators, or artificial muscles, particularly as electroactive polymers (EAPs).{{cite book |editor-last1=Shahinpoor |editor-first1=Mohsen |editor-last2=Schneider |editor-first2=Hans-Jorg |title=Intelligent materials |date=2007 |publisher=RSC Publishing |isbn=978-0-85404-335-4}}{{Page needed|date=July 2020}}{{cite book |editor-last1=Schwartz |editor-first1=Mel |title=Encyclopedia of smart materials |date=2002 |publisher=John Wiley and Sons |isbn=9780471177807}}{{Page needed|date=July 2020}}{{cite book |last1=Nakanishi |first1=Takashi |title=Supramolecular soft matter : applications in materials and organic electronics |date=2011 |publisher=John Wiley & Sons |isbn=9780470559741}}{{Page needed|date=July 2020}}{{cite book |last1=Gaudenzi |first1=Paolo |title=Smart structures : physical behaviour, mathematical modelling and applications |date=2009 |publisher=John Wiley & Sons |isbn=978-0-470-05982-1}}{{Page needed|date=July 2020}}{{cite book |last1=Janocha |first1=Hartmut |title=Adaptronics and smart structures : basics, materials, design, and applications |date=2007 |publisher=Springer |isbn=978-3-540-71967-0 |edition=2nd, revised}}{{Page needed|date=July 2020}}{{cite book |last1=Schwartz |first1=Mel |title=Smart materials |date=2009 |publisher=CRC Press |isbn=9781420043723}}{{Page needed|date=July 2020}}

Types

There are a number of types of smart material, 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 a reverse manner, a voltage across the sample will produce stress within 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 materials in which large deformation can be induced and recovered through temperature changes or stress changes (pseudoelasticity). The shape memory effect results due to respectively martensitic phase change and induced elasticity at higher temperatures.
  • Photovoltaic materials or optoelectronics convert light to electrical current.
  • Electroactive polymers (EAPs) change their volume by voltage or electric fields.
  • Magnetostrictive materials exhibit a change in shape under the influence of magnetic field and also exhibit a change in their magnetization under the influence of mechanical stress.
  • Magnetic shape memory alloys are materials that change their shape in response to a significant change in the magnetic field.
  • Smart inorganic polymers showing tunable and responsive properties.
  • pH-sensitive polymers are materials that change in volume when the pH of the surrounding medium changes.{{cite journal | vauthors = Bordbar-Khiabani A, Gasik M | title = Smart hydrogels for advanced drug delivery systems | journal = International Journal of Molecular Sciences | volume = 23 | issue = 7 | pages = 3665 | doi = 10.3390/ijms23073665 | doi-access = free }}
  • Temperature-responsive polymers are materials which undergo changes upon temperature.
  • Halochromic materials are commonly used materials that change their color as a result of changing acidity. One suggested application is for paints that can change color to indicate corrosion in the metal underneath them.
  • Chromogenic systems change color 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 colour 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.
  • Ferrofluids are magnetic fluids (affected by magnets and magnetic fields).
  • Photomechanical materials change shape under exposure to light.
  • Polycaprolactone (polymorph) can be molded by immersion in hot water.
  • Self-healing materials have the intrinsic ability to repair damage due to normal usage, thus expanding the material's lifetime.
  • Dielectric elastomers (DEs) are smart material systems which produce large strains (up to 500%) under the influence of an external electric field.
  • Magnetocaloric materials are compounds that undergo a reversible change in temperature upon exposure to a changing magnetic field.
  • Thermoelectric materials are used to build devices that convert temperature differences into electricity and vice versa.
  • Chemoresponsive materials change size or volume under the influence of external chemical or biological compound.Chemoresponsive Materials /Stimulation by Chemical and Biological Signals, Schneider, H.-J.; Ed:, (2015)The Royal Society of Chemistry, Cambridge https://dx.doi.org/10.1039/97817828822420

See also

References

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