The shape-memory material is a term used to describe a type of materials/fabrics that return to a specific shape, after being exposed to specific temperatures. This process of changing can be repeated several times and therefore are materials capable of remembering their original shape. Regarded as intelligent textile. Shape-memory alloys (e.g. Cu–Zn–Al, Fe–Ni-Al, Ti-Ni alloys) are already in use in biomedical applications; Such as guidewires, orthodontic wires as cardiovascular stents. The shape-memory effect of these materials based on a martensitic phase transformation. Shape memory alloys, such as nickel-titanium, are used to provide increased protection against sources of (extreme) heat.
Material properties and variation in temperature
The material properties get activated by variations in temperature, below or above or two-way activation. Therefore, a reversible variation of the shape is possible, which is a necessary condition for protection purposes in textiles used to resist changeable weather conditions. In products, a shape-memory alloy is usually in the shape of a spring, Incorporated in layers so that materials above it might change shape closer to body temperature. For clothing applications, the desired temperatures for the shape-memory effect to occur will be close to body temperature. Established applications for shape-memory alloys also include domestic appliances (e.g. shower mixer valves, coffee makers and rice cookers) and utility applications (e.g. safety shut-off valves for fuel lines in the event of a fire, and air-conditioning systems). See Smart textiles