Unit 3

Question 1

Modern Material

Answer 1

A material that has been engineered to have improved properties.

Question 2

Graphene

Answer 2

• modern material
• a single carbon layer material
• hypothetically 100 times stronger than steel.

Question 3

Titanium

Answer 3

• modern material
• used in sporting and medical applications
• it has a high strength-to-weight ratio and is resistant to corrosion

Question 4

Metal foam

Answer 4

• modern material
• strong but lightweight
• produced by injecting a gas or foaming agent into molten metal.
• often used in vehicles such as planes and cars as they absorb shock effectively

Question 5

Liquid crystal displays (LCDs)

Answer 5

• modern material
• The liquid crystals are between a liquid and solid state. —When charge is applied to each liquid crystal, the shape changes to either block light or let light through.
• This ensures text or images display on the LCD.

Question 6

Nanomaterials

Answer 6

• modern material
• tiny particles of 1 to 100 nanometres (nm) that can be
• used in thin films or coatings
• smartphone screens that repel greasy fingerprints, or hydrophobic materials that repel water.

Question 7

What are some examples of modern materials?

Answer 7

Graphene, Titanium, Metal foam, Liquid crystal displays (LCDs), Nanomaterials

Question 8

Smart materials

Answer 8

exhibit a physical change in response to some external stimuli.

Question 9

Shape-memory alloys (SMA)

Answer 9

• smart material
• metal alloys that can remember their shape when heated.
• used for braces

Question 10

Thermochromic pigments

Answer 10

• smart. material
• change colour when their temperature changes.
• can be mixed with paint or polymers to give the materials the same colour-changing properties

Question 11

Photochromic pigments

Answer 11

• smart material

- change their properties when exposed to ultraviolet (UV) light.

Question 12

Quantum-tunnelling composite (QTC)

Answer 12

• smart material
• an insulating rubber containing tiny particles of metal.
• an insulator when resting and a conductor when pressure is applied.

Question 13

Self-healing materials

Answer 13

• smart material

- have the ability to repair themselves, which can extend the lifespan of the products that use them.

Question 14

Polymorph

Answer 14

• smart material
• polymer that becomes malleable when heated to about 62°C.
• When it cools down it becomes hard enough to drill and cut.
• good for modelling

Question 15

Composite materials

Answer 15

-are made up of different materials which are combined to improve their properties.

Question 16

Three types of composite materials:

Answer 16

fibre-based composites
particle-based composites
sheet-based composites

Question 17

fibre-based composites

Answer 17

Glass-reinforced plastic (GRP):
Materials-Glass fibres and resin
use- Boats, instrument cases

Carbon-reinforced plastic (CRP)
materials-Carbon fibre and resin
use-Formula 1 car bodies, crash helmets, sports equipment

Glass-reinforced concrete (GRC)
materials- Glass fibre and concrete
use-Street furniture, urban features

Question 18

Particle based composites

Answer 18

Concrete:
Materials-Cement, sand and aggregate
Use-Buildings, street furniture
Cermet
Materials-Ceramic (cer) and metal (met)
Use-Electronic components that need to operate under very hot temperatures

Question 19

sheet-based composites

Answer 19

Medium-density fibreboard (MDF)
Materials-Wood pulp and resin
Use-Furniture and interior cladding
Plywood
Materials-Wood veneers and resin
Use-Furniture and construction
Chipboard
Materials-Wood chip and resin
Use-Furniture panels and construction

Question 20

Conductive fabrics

Answer 20

• technical textile
• allow a small electrical current to safely pass through them.
• eg: touchscreen gloves

Question 21

Fire-retardant fabrics

Answer 21

• technical textile
• more resistant to fire
• through chemical treatment or manufactured fireproof fibers .

Question 22

Kevlar

Answer 22

• technical textile

- has great impact resistance.

Question 23

Microfibres

Answer 23

• technical textile

- can be coiled to provide a very warm, soft or absorbent material that can be used in winter clothes or products