11. Smart materials Flashcards
1
Q
What are smart materials?
A
materials whose physical properties change in response to a change in the environment
2
Q
What are smart materials?
(examples)
A
- SMAs
- thermochromic pigment
- phosphorescent pigment
- photochromic pigment
- electroluminescent wire
- piezoelectric material
3
Q
What are the properties of SMAs?
A
- changes shape in response to a change in temperature or electrical input
- e.g. nitinol
4
Q
What are the uses of SMAs?
A
- dental braces
- self-closing windows
- aeroplane wing flaps
- bioengineering such as stents, bone plates and screws
5
Q
What are the properties of thermochromic pigment?
A
- changes colour in response to temperature change
6
Q
What are the uses of thermochromic pigment?
A
- room thermometers
- medical thermometers for children
- bath water thermometers
- colour changing mugs and kettles
- food packaging to indicate food is too hot to eat or cool for drinks
- baby feeding spoons
- battery charge indicator strips
7
Q
What are the properties of phosphorescent pigment?
A
- absorbs light energy during the day and ‘re-emits’ the light energy when its dark
8
Q
What are the uses of phosphorescent pigment?
A
- fire exit signs
- ‘glow in the dark’ products such as adhesive stars, night lights, masks, watch hands
9
Q
What are the properties of photochromic pigment?
A
- changes colour with light intensity
10
Q
What are the uses of photochromic pigment?
A
- welding goggles
- reactive spectacle lenses
- security markers that show up under UV light
11
Q
What are the properties of electroluminescent wire?
A
- thin copper wire coated in a phosphorescent material that glows in response to alternating current
12
Q
What are the uses of electroluminescent wire?
A
- glow bracelets
- interweaving for clothing
- home decoration
- outdoor decorative lighting
13
Q
What are the properties of piezoelectric material?
A
- gives off a small electrical charge when deformed
- increases size when an electrical current is passed through it
14
Q
What are the uses of piezoelectric material?
A
- airbag sensors in cars
- lighters for barbecues
- vibration damping in tennis racquets
- musical greetings cards
- pressure sensors
