Alan Hooper
Advanced Materials, QinetiQ, UK
The key to 21st century competitive advantage will be the development of products with increasing levels of functionality. This will include structural and non-structural functions, individually and in combination, both active and passive. It will apply both to large structures, fixed and mobile, and to consumer products, including textiles and clothing. Smart Materials will play a critical role in this development.
The table below summarises the classes of material that are commonly referred to as being ‘smart’, together with their corresponding pairs of stimuli and response variable parameters; e.g., photochromic – light – colour change.
 |
Electrical |
Magnetic |
Optical |
Thermal |
Mechanical |
| Electrical |
 |
|
Electrochromic Electroluminescent Electro-optic |
Thermoelectric |
Piezoelectric Electrostrictive ER fluids |
| Magnetic |
|
|
Magneto-optic |
|
MR fluids Magnetostrictive |
| Optical |
Photoconductor |
|
Photochromic |
|
|
| Thermal |
|
|
Thermochromic Thermoluminescent |
|
Shape memory |
| Mechanical |
Piezoelectric Electrostrictive |
Magnetostrictive |
Mechanochromic |
|
Negative Poisson ratio |
Stimulus-response matrix for selected smart materials
(ER fluids – electro-rheological fluids; MR fluids – magneto-rheological
fluids)
‘Smart’ or ‘Functional’ materials usually form part of a ‘Smart System’ that has the capability to sense its environment and the effects thereof and, if truly smart, to respond to that external stimulus via an active control mechanism. Often, the sensing function alone is taken as sufficient to constitute ‘smartness’. Smart materials and systems occupy a highly interactive ‘technology space’ which also includes the areas of sensors and actuators, together with other generic platform technologies such as biomimetics and nanotechnology. Additional, more narrowly defined related topics, such as ‘tagging’, also sit in this technology space. There is no shortage of potential technical solutions in this area but, equally, no single solution will fit all applications. The need is, rather, to enhance the practical realisation of the existing materials-based technologies, tailored to particular customer and market requirements. Key drivers will include materials and device integration within the relevant substrate, miniaturisation, connectorisation, durability and cost. Specifically in the smart clothing arena, systems must be affordable and be able to pass the washing machine test. Applications for ‘Smart’ clothing will include healthcare and telemedicine; military, police and emergency service equipment; entertainment, sports and leisure; and fashion wear. Wearable electronics will support the development of distributed computing and communications systems and provide benefits in support of major Foresight initiatives, such as crime prevention and the ageing community. Alan Hooper is chair of the Smart Textiles and Systems Committe at the Institute of MaterialsI http://www.iom3.org and is a technology translator for the newly launched DTI - supported Knowledge Transfer Network Smart.Mat Network. Please go to http://www.smartmat.org and register (membership is free) Research bodies working within Smart Textiles Smart Textiles Research Center "E. Piaggio", University of Pisa Smart Fabrics and Interactive Textiles Expanding into New Markets - Report Wearable Computing Lab: Electronic Textiles Technical Textiles
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