After 30 years’ research in the field of nanoscience, there are today more than 200 products on the market which have been developed using this technology. The particles have long been used in coloured glass, but they are also increasingly being used as colour in tyres, paints, concrete, UV-filters in sunscreen products and in cosmetics.
Nano surfaces which repel dirt can be found in some frying pans and textiles. Water-repellent nano-molecules repel water, dirt and bacteria in hospital equipment. Windscreen wipers will be a thing of the past when the windscreens in cars are covered with a layer of transparent particles which are hard, scratch-resistant and water repellent.
In the future, the technology will be used to create new materials with tailored properties. Products in the areas of optics, electronics, energy and memory storage will become smaller, better and cheaper since more capacity can be created on a smaller surface.
Nanotechnology can be regarded as a platform for different areas of science, in which new materials are developed or already existing materials are given new properties. The technology can also open doors in areas such as physics, bio- technology and medicine. More than 30 countries are currently running national nanotechnology research programmes. Chalmers University of Technology, the Faculty of Engineering at Lund University and the Royal Institute of Technology in Sweden are holding their own in international terms.
Chromogenics produces smart windows, motorcycle visors and skiing goggles
The Uppsala-based company Chromogenics is developing a technology based on thin plastic foil with built-in memory. Skiing goggles and helmet visors can be adapted to extremely varied light condition, and windows covered in the foil reduce the need for air conditioning. The environmental benefit of these products, which will soon be launched on the market, lies in reduced energy consumption.
This is how it works: a foil is created by sandwiching several layers of different materials between two layers of plastic film. The tint of the foil changes if it is subjected to a weak electric current, which causes ions to move from one layer to another. For example, ions from a nickel-oxide layer which migrate into a layer of tungsten oxide via a polymer electrolyte can make both layers darker. If the polarity is changed, the ions migrate the other way, and the layers become lighter. An electronic control unit regulates the tint intensity and the desired optical properties are stored in a memory. Since electricity is only used when the tint intensity changes, the foil is energy-efficient.
Environmental benefits in the electronics industry
The Swedish company Obducat is a world-leader in nanoimprint lithography (NIL). The technology can be used to make exact micro- and nano-sized copies in polyester film of an original which may have been made in an electron beam printer. Lithography technology is used, for example, to create memory media, display technology, semiconductors and bio sensors. It improves the efficiency of material consumption, ensure lower energy consumption when the product is in use and reduces the amount of waste when products are scrapped.
Multifunctionality, i.e. the ability of one product to perform several different functions, may be one way to save the environment. In the future, windows may be used to turn light into electricity, darken automatically and act as displays for moving images. If organic polymer chains are woven into textiles, the result may be a television screen which can be carried on a sweater or an electronic newspaper where pictures and text are updated continuously.
Lighting is an exciting environmental area. LEDs (Light Emitting Diodes) containing nano-thin layer systems will save large amounts of energy while, at the same time, providing significantly brighter light than today’s light bulbs. The light emitting diodes may be made self-sufficient if they are linked to technology which collects daylight to produce electricity in the same way that plants use photosynthesis.
Examples of future applications for nanotechnology
- Fuel cells the size of a postage stamp can already be produced. Once three-dimensional nano surfaces are introduced, capacity will increase and more light-efficient fuel cell-powered engines will be produced, for example, for bicycles.
- It will soon be possible to design buildings in such a way that energy emitted by the buildings can be recovered via three-dimensional energy-accumulating nanocomponents.
- Electric charges are produced when nanothreads made from zinc oxide are bent. Thousands of threads can be integrated with electrodes and produce electricity when the threads move sideways and up and down. Clothes made from such threads can generate electricity which, in turn can power equipment which monitors the wearer’s health or make him or her visible to traffic.
- The paintwork on cars can collect light to charge the batteries and regulate the temperature inside the car. Surplus heat is turned into electricity via heat extraction pumps. Safety systems, such as the brakes, may contain nanosensors to improve the sensitivity of the system.
- Tennis rackets may be made stiffer and more powerful by using carbon nanotubing. Tennis balls will not lose their bounce for several weeks if they are treated with a layer of nanoparticles on the inside which allows the gas to remain inside the ball longer.
Nanotechnology is based on particles so small that they are invisible to the naked eye. The technology operates at nano-level, i.e. where a nanometre is one-millionth of a millimetre (10-9 m). Particles of this size exist around us in the form of volcanic ash, clay and marine aerosols. They can also be formed through incomplete combustion.
This article was first published in Advantage Environment printed in February 2008
Updated March 2009