Smart Materials

Question 1

What are smart materials?

Answer 1

Materials that react with external stimulus or input
Alter functional or aesthetic properties in response to changing environment
Stimulus:
- heat
- pressure
- moisture
- pH levels
- etc 
Examples:
• thermochromic pigments
• photochromic pigments
• shape memory alloys

Question 2

Thermochromic pigments

Answer 2

React to change in temperature
Indicate a particular temperature is been reached
Incorporated into a material
• plastics
• paint
Babies feeding spoons
Mugs that change colour

Question 3

Photochromic pigments

Answer 3

React to UV rays
Create a colour change in material
Nail varnish, t-shirts and vehicle spray paint
Sunglasses - silver halides - darken in sun

Question 4

Shape memory alloys (SMAs)

Answer 4

Regain their original shape
Nitinol - nickle and titanium
• dental braces - wire shrinks from heat
• surgical stents - expand blood vessels
• electrical current - contracts