Dt Gcse Revision: Smart Materials

SMART Materials A SMART material is a material that is affected by outside influence. Polymorph * Type of thermoplastic (can be reshaped many times). * Normally supplied in form of granules or small plastic beads. * Low fusing temperature of around 60Â °C. This means it can be reduced to a mouldable condition by immersion in hot water. * Once fused turns from opaque to clear. * Heating above 65Â °C is dangerous as it will become a sticky-adherent mass, similar to hot-melt glue. Polymorph has high molecular weight and great tensile strength, and therefore suited for applications where mechanical strength is important. * Some uses are: Mould-making (i. e Gum-shields), general DIY materials, making a polymorph skeleton to support other materials, trainer/shoe components. QTC (Quantum Tunnelling Composite)* QTC is a composite material made from conductive filler particles combined with an elastomeric binder, typically silicone rubber. QTC Material has the unique ability to smoothly cha nge from an electrical insulator to a metal-like conductor when placed under pressure. * While in an unstressed state the QTC Material is a near-perfect insulator; with any form of deformation the material starts to conduct and with sufficient pressure metallic conductivity levels can be achieved. * QTCâ„ ¢ Material can be formed or moulded into virtually any size, thickness or shape. * QTCâ„ ¢ Material is mechanically strong. QTCâ„ ¢ Material can be made to withstand extreme temperatures limits. * Used for switches and keyboards. Thermochromic Ink * These materials change colour when there is a change in temperature. * Thermochromic ink comes in two forms: Liquid crystals and Leuco dyes. * Leuco dyes are easier to work with and allow for a greater range of applications. * Applications of thermochromic ink include: flat thermometers, battery testers, clothing. Mr Tsiang