1.11 Smart Materials

Question 1

Describe smart materials

Answer 1

Materials whose physical properties change in response to an input or change in the environment, such as electricity, pressure, temperature or light.

Question 2

How does SMAs work?

Answer 2

Changes shape in a response to a change in temperature or electrical input

Question 3

State two uses of SMAs

Answer 3

• Dental braces
• Self-closing windows
• Aeroplane wing flaps
• Bioengineering, such as stents, bone plates, screws

Question 4

How does thermochromic pigment work?

Answer 4

Changes colour in response to temperature

Question 5

State three uses of thermochromic pigment

Answer 5

• Room thermometers
• Medical thermometers, for children
• Bath water thermometers
• Colour change mugs and kettles
• Food packaging
• Baby feeding spoons
• Battery charge indicator strips

Question 6

How does phosphorescent pigment work?

Answer 6

Absorb light energy during the day and ‘re-emits’ the light energy when it is dark

Question 7

State two uses of phosphorescent pigment

Answer 7

• Fire exits signs

- ‘Glow in the dark’ products, such as adhesive stars, masks, night lights, and watch bands

Question 8

How does photochromic pigment work?

Answer 8

Changes colour with light intensity

Question 9

State two uses of photochromic pigment

Answer 9

• Welding goggles
• Reactive spectacle lenses
• Security marker that shows up under UV light

Question 10

How does electroluminescent wire work?

Answer 10

Thin copper wire coated in a phosphorescent material that glows in response to an alternating current

Question 11

State two uses electroluminescent wire

Answer 11

• Glow bracelets
• Interweaving for clothing
• Home decoration
• Outdoor decoration lighting

Question 12

How does piezoelectric material work?

Answer 12

Gives off a small electrical charge when deformed

Increase in size (up to 4%) when an electrical current passed through it

Question 13

State two uses piezoelectric material

Answer 13

• Airbag sensors in cars
• Vibration damping in tennis racquets
• Lighters for barbecues
• Musical greeting cards
• Pressure sensors