1.1-Classification of Smart Materials, Modern Materials, Composite Materials and Technical Textiles

What are smart materials?

•Materials that change their properties (output) in response to an input/change in the environment, which often return to their original state when the stimulus is taken away

•Some examples of the relevant inputs include the following:

•Electricity

•Temperature

•Light

•Stress

•Moisture

•pH

What are examples of smart materials?

•Shape memory alloys

•Photochromic pigments

•Thermochromic pigments

•Phosphorescent pigments

•Electroluminescent wire

•Piezoelectric material

What is the classification, output and uses of shape memory alloys (SMAs)?

•Classification: smart material

•Output: changes shape/deforms in response to temperature/electricity input

•Uses: dental braces, self-closing windows, bioengineering such as stents, bone plates and screws

How does dental braces achieve its function?

This shape memory alloy’s nitinol wire changes length in response to a change in temperature

What is the classification, output and uses of thermochromic pigments?

•Classification: smart material

•Output: changes colour in response to temperature change

•Uses: room thermometers, medical thermometers for children, colour change mugs and kettles, food packaging in order to indicate whether or not food is hot/cold for consumption

What is the classification, output and uses of phosphorescent pigment?

•Classification: smart material

•Output: absorbs light energy input during the day and ‘re-emits’ the light energy output when it’s dark

•Uses: fire exit signs, glow in the dark products such as adhesive stars, night lights

What is the classification, output and uses of photochromic pigment?

•Classification: smart material

•Output: changes colour in response to light intensity input

•Uses: welding goggles, reactive spectacle lenses, security markers that output as a result of UV light input

What is the classification, manufacture, output and uses of electroluminescent wire?

•Classification: smart material

•Manufacture: coat thin copper wire in a phosphorescent material

•Output: glows in response to an alternating current (AC) input

•Uses: glow bracelets, interweaving for clothing, home decoration, outdoor decorative lighting

What is the classification, output and uses of piezoelectric material?

•Classification: smart material

•Output: releases a small electrical charge in response to the deformation/stress input

•Uses: air bag sensors for cars, pressure sensors, lighters for barbeques, vibration damping for tennis rackets

What are modern materials?

A material that has been engineered to enhance properties such as mechanical, physical/optical properties of materials that define how they behave in use/functionality

What are some examples of modern materials?

•Composite materials such as GRP, CRP

•Technical textiles such as Kevlar, Nomex

What are composite materials?

Materials that are made from two or more materials, often with contrasting properties. Furthermore, combining the properties of the different materials can lead to development of new and improved materials

What are some examples of composite materials?

•Glass reinforced plastic (GRP)

•Carbon reinforced plastic (CRP)

•Concrete

What is the classification, manufacture and uses of glass reinforced plastic (GRP)?

•Classification: composite material, modern material

•Manufacture: combines glass fibres with a thermosetting plastic in order to output a lightweight and strong material

•Uses: boat hulls, car bodies

What is the classification, manufacture and uses of carbon reinforced plastic (CRP)?

•Classification: composite material, modern material

•Manufacture: combines carbon fibres with a thermosetting plastic in order to output a material that is more rigid, stronger, lighter, more expensive and more brittle than glass reinforced plastic (GRP)

•Uses: sports equipment

What are technical textiles?

Textiles that are manufactured for functionality rather than aesthetics

What are some examples of technical textiles?

•Kevlar

•Conductive textiles

•Nomex (fire-resistant fabrics)

•Microfibres

What is the classification, properties and uses of Kevlar?

•Classification: technical textile, modern material

•Properties: high tensile strength-to-weight ratio, tough

•Uses: protective armour

What is the classification, manufacture, properties and uses of conductive textiles?

•Classification: technical textile, modern material

•Manufacture: metal fibres are spun into the fabric/metal-based powders are impregnated (coated) into the fabric

•Properties: good electrical conductivity

•Uses: sensors

What is the classification, properties and uses of Nomex (fire-resistant fabrics)?

•Classification: technical textile, modern material

•Properties: thermal resistant as a result of flame resistance being built into their chemical structure

•Uses: circuit boards

What is the classification, properties and uses of microfibres?

•Classification: technical textile, modern material

•Properties: breathable, durable

•Uses: sports clothing