Modern & Smart Materials
GCSE — 2.1.2 In-depth Knowledge: Product Design
Differences between modern and smart materials
- Modern materials are designed to have specific properties and characteristics to improve existing materials. They are relatively new with specific working properties and performance characteristics.
- Smart materials have unique changes that occur in response to external stimuli — making them react in a clever way.
Modern materials
Carbon fibre
Carbon fibre has several advantages:
- High stiffness and high tensile strength
- Low weight and high temperature tolerance
- High chemical resistance and low thermal expansion
- Resistance to corrosion
Carbon atoms are bonded together in crystals and woven into fabric. Carbon fibres are usually combined with other materials to form a composite. Layers of woven carbon fabric are bonded to create complex shapes for products like racing bicycles, Formula One cars, aerospace vehicles, and sporting products where strength, lightweight properties and speed are essential.
Kevlar
Kevlar is a heat-resistant and strong synthetic fibre with the ability to stop bullets and knives from penetrating it. Often described as five times stronger than steel for its weight. It can be woven into different shapes, remains lightweight and flexible — ideal for protective vests.
GRP — Glass Reinforced Polymer (fibreglass)
Fibre strands are embedded into a polymer resin matrix, resulting in high compressive and tensile strengths. Products include water slides, jacuzzis, car body panels, boats and roofing products.
Styrofoam
Styrofoam is a trade name for expanded polystyrene foam (also called blue modelling foam). Available in various sheet sizes and thicknesses. Easy to cut, shape and work, with excellent insulation properties.
Modelling foam board
An eco-friendly versatile material used for framing, mounting design work and creating scale architectural models. A dense layer of foam sandwiched between two thin card faces. Non-toxic and acid free, with anti-UV finishing. Can also be laser cut.
Smart materials
Smart material — a category of materials that react when triggered by an external stimulus such as temperature, light or pressure.
QTC — Quantum Tunnelling Composite
A black rubbery material which is an electrical insulator in its normal state, but when placed under compression, it becomes a conductor. Used in clothing, smartphones and outdoor equipment as electrical switches.
Photochromic materials
Photochromic pigments or film change colour in ultraviolet (UV) light. Used in spectacles that automatically darken as sunlight gets brighter, and in high-rise buildings to prevent strong sunlight penetrating inside.
Thermochromic materials
Thermochromic pigments change colour in response to temperature. Useful in baby products like spoons, bottles and bath toys to indicate temperature.
Shape Memory Alloys (SMAs)
Materials that change shape when heated and return to their original shape.
- Nitinol (nickel + titanium) — spectacle frames made from Nitinol can be returned to their original shape easily; dental braces made from Nitinol can help straighten teeth.
Polymorph
A polymer that becomes malleable at 62°C. Can be moulded by hand when warm, sets rigid when cooled, and can be reheated and reshaped repeatedly.