New smart materials Brian Russell Exam expectations This

New & smart materials Brian Russell

Exam expectations This is a new topic for the examination and it is likely to be tested regularly. You will be expected to be able to explain the difference between a new and a smart material. You will also be expected to describe an application for a new or smart material

New modern materials • There have been massive advances in new materials that it is difficult to keep up to date with what is available. These developments are one of the best examples of technological push as sometimes the properties of the materials are discovered through extensive research and experiments then a useful application found for them later.

Smart materials • Smart materials are ones which react and change their properties in response to an input such as electrical current, heat, light etc. They have particularly useful applications in areas of safety, for example, where they can give off warnings of heat.

Starch based polymers Recent experiments in creating biodegradable polymers from corn, maize or potato starch have started to have a large impact upon the packaging industry, for example. Some major high street stores have already changed to these materials for food packaging.

Spud forks • • Made from 80% potato starch, 20% Soya oil. Can be washed in dishwasher Totally biodegradable in just 180 days! Made by Spud. Ware

Compostableware PAPCo. RN are two industrial designer who work with materials which are compostable. They work in the latest plastics, which are based on renewable resources such as wheat, maize and lactic acid. All these products have a limited environmental impact, from beginning to end and form part of nature’s own cycle. They aim to combine good design with a vision of reducing environmental damage

Benefits of starch based polymers As oil based polymers generally do not break down and give off toxic fumes if burned these alternative polymers offer a real long term solution to environmentally friendly packaging and product needs.

Precious Metal Clays • The revolution in precious metal clays has transformed some of the jewellery markets, opening avenues for creativity which previously had been hindered by complex manufacturing processes.

Precious Metal Clays This relatively new material is made from 99. 9% fine particles of metal (usually silver) mixed with a binder and water. It looks like and is worked like clay but when dried then heated to around 800 degrees the metal particles fuse together and it becomes solid metal.

Quantum Tunnelling Composite These exciting new materials are metal filled polymers which have the property of changing from an insulator to a conductor when pressed. The more it is squeezed the closer the metal particles squash together and the easier it becomes for the electrons to pass between them.

Quantum Tunnelling Composite Initially used in space suits to allow control panels to be integrated into the fabric these QTCs are being used in clothing so that devices such as Ipods can be integrated into the garment.

Quantum Tunnelling Composite Heating applications such as temperature controlled clothing and high visibility clothing are just two of the many applications of incorporating electronics into textiles.

Carbon fibres are usually woven into a fabric sheet and then impregnated with an epoxy or phenolic resin and forced into a mould. The material is then cured (or set) with heated steam to create a very strong lightweight material. This is also an example of a composite material

Carbon fibre Formula One racing car bodies, cycle design, and sports equipment have all benefitted from the application of this material.

Foamed Metals Aluminium, for example, can be processed so that it foams. When sandwiched between two solid sheets it produces a material which is lighter, stiffer and more resistant to impact than solid sheet as the foam core absorbs and disperses the energy around the small cells walls. This is particularly useful in vehicle design, for example.

3 D veneers Usual veneers of different wood species and thicknesses are prepared mechanically to become distortable. This is the basis for 3 D forming capabilities (bending in two directions). 3 D veneers become more stable if several layers are glued preferably with grains crossing. They can also be applied as a single layer to a carrier panel such as MDF.

Maplex looks similar to MDF but is made from 100% pressed wood fibers, with no binding agents. The lack of chemical binding agents makes the material completely biodegradable and recyclable. It can be moulded into interesting forms.

Kevlar Weight for weight this flexible plastics –based material is five times stronger than steel. It is usually woven and used in layers. Used for body armour and stab-proof vests. Another application is it is used to replace steel in racing tyres.

Breathable fabrics (Gore Tex) Gore-Tex is manufactured from polytetrafluoroethylene (PTFE). Used in a wide variety of applications such as high performance fabrics, medical implants, insulation for wires and cables, gaskets, and sealants. However, Gore -Tex is best known for its use in protective, yet breathable, rain wear.

Polycaprolactone (PCL) PCL is a low melting point, biodegradable thermoplastic material widely used in medical applications. In schools it is known as Polymorph and can easily be shaped by hand to resemble injection moulded products

Smart materials These materials can be grouped by how they react to their environment: • • • Colour changing Light-emitting Moving materials Temperature changing Thickness changing

Photochromic materials • These materials change colour in response to changes in light. • Some glasses have reactive lenses which become darker as the light increases

Thermochromic materials • These materials change colour in response to changes in temperature. Kettles and baby feeding products are just two applications where it is useful to have a built in thermometer.

Electroluminescent materials These materials can produce brilliant light of different colours when an electrical current is passed through them. This produces no heat and is used to create display panels which are just a few millimetres thick.

Fluorescent materials These materials produce light when exposed to Ultra Violet (UV) rays. The light stops when the UV radiation is removed. UV rays are invisible to the eye.

Phosphorescent materials These materials produce light after they have been exposed to a light source, which is later removed. Warning signs often use these materials.

Piezoelectric materials These materials convert mechanical energy to electrical energy and electrical energy to mechanical energy. Flashing shoes is one of many uses.

Shape memory alloys Some metals can be heat treated so that the metal gains a memory. One of the most common is called Nitinol and is an alloy of nickel and titanium. This material as a wire will shrink by about 5% of its length when an electrical current is passed through it. It can be stretched back to its original size once the current is turned off. This has particular applications in bioengineering where is can be placed into collapsed blood vessels or around broken bones.

Shape memory alloys are also used in some spectacle frames and these superelastic alloys can be squashed beyond the point other frames would snap and will return to their original shape at room temperature.

Thermoelectric materials These materials convert body heat into electricity by using a combination of materials (metals or ceramics) that are poor thermal conductors and good electrical conductors. Using body heat to energize small electrical products. This technology has been available since 1989 when Seiko introduced the "Thermic Wrist. Watch"

Magneto-rheological fluids These fluids become solids when placed in a magnetic field. They can be used to construct dampers which suppress vibrations and are used on some high performance cars such as Ferraris.

Nanotechnology This area of science deals with materials at an atomic or molecular scale and is creating opportunities to develop materials which just a few years ago would have been considered as science fiction. Whilst there are some massive health and safety issues with dealing with materials which are so small that they could enter the bloodstream and travel into the brain, this has major benefits in the delivery of drugs to affected parts of the body, for example.

Nanotechnology Anti-microbial agents added in food packaging, UV protective cosmetics, increasing the strength of polymers to replicate properties of metals and making surfaces harder wearing are just some of the current applications for this technology although it is the development of newer, smarter, more reactive materials where this is likely to have the greatest impact.

Nanotechnology – the future • We can only guess the impact that nanotechnology will have on the products we purchase in the future. • Products using nanotechnology are doubling each year • Clothing, cosmetics, dietary supplements, drugs and electronics areas where there is currently massive investments taking place.