Smart Materials

Question 1

CH
Def
Changes in temperature

Answer 1

They are materials who’s physical properties change in response to a change in environment such as a change in pressure, electricity, temperature or light

Most common SMA is nitinol.
When heated to certain temp, it will return to original shape
Transition temp can be dictated passing electrical current through it

Question 2

SMA

Answer 2

Shape memory alloys
Dental braces, self closing Windows, airplane flaps, bioengineering eg stents, bone plates, screws
Changes shape in response to change in temperature or electrical input. Eg Nitinol
(In dental braces it changes lengthy when it meets body temp)

Question 3

Thermochromic pigments

Photochromic pigments

Answer 3

Thermo Changes colour with response to temperature
Thermometers, colour change mugs and kettles, food packaging to indicate hot or cold, battery charge indicator strips

Photo Changes colour with light intensity
Welding Goggles, security markers that show up under UV

Question 4

Phosphorescent pigment

Electroluminescent wire

Piezoelectric material

Answer 4

Absorbs light in day, re-emits light e when dark
Fire signs, glow in the dark products,

Electroluminescent - thin copper wire coated in phosphorescent material that glows when AC passes
Outdoor decorative lighting, glow bracelets, home decoration

Piezoelectric - gives off small electric charge when deformed, and vice versa
Airbag sensors, barbeque lighters, pressure sensors, musical greeting cards