5.9 - Smart Materials
Smart materials
- A smart material is one whose properties change reversibly in response to a change in its surroundings (such as temperature, light or pH).
- The property that changes is usually its colour, transparency or shape.
The five types of smart material
- Thermochromic pigments - Change colour when heated or cooled. Used in baby bath toys and feeding spoons to show if something is too hot.
- Photochromic pigments - Change colour as light intensity changes (e.g. sunglasses lenses that darken in bright sunlight).
- Polymer gels (hydrogels) - Absorb or release water in response to a change in pH or temperature, expanding or shrinking by up to a thousand times.
- Shape memory alloys - Return to their original shape when heated after being bent (e.g. glasses frames).
- Shape memory polymers - Return to their original shape when heated, but are made from a polymer rather than a metal alloy.
TermDefinition
Smart materialA material whose properties change reversibly in response to a change in its surroundings.
Thermochromic pigmentA material that changes colour when heated or cooled.
Photochromic pigmentA material that changes colour as light intensity changes.
Polymer gelA material that absorbs or releases water in response to a change in pH or temperature.
Shape memory alloyA metal alloy that returns to its original shape when heated after being bent.
Shape memory polymerA polymer that returns to its original shape when heated after being bent.