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Where small things make a BIG difference
Nanotechnology deals with things at an incredibly small scale; the nanometre scale, or one-billionth of a metre. To put this into perspective, think of a marble sitting on the surface of the Earth. If the marble was one nanometre wide, then the entire Earth would be only one metre across!This is your guide to the emerging science of nanotechnology, a field with the potential to bring big social, economic, and environmental benefits to you and the world. Discussing Australian research from CSIRO and other institutes, and overseas research, it covers the topics of nanotechnology in consumer products, health and food, water and the environment, energy development, and nanosafety and regulation.
At the nanoscale, substances may behave differently or better compared to the same substances at macro sizes. For instance:
- gold can change colour
- carbon can conduct heat and electricity better
- silver has improved antimicrobial properties.
- becoming super-elastic
- becoming more chemically reactive
- getting physically stronger or weaker
- being able to cope with massive changes in temperature and pressure.
It’s because of these unique properties that nanotechnology could be used in such a huge range of products.
Nanoproducts
There are socks that repel odour, UV-blocking invisible sunscreens, self-cleaning dog beds, super-light tennis racquets and anti-fungal sports towels that won’t stink your bag out after the match. Nanotechnology isn’t just helping you smell nice and play tennis; it also has applications that could make major differences to society. Nanotechnology-based house paints reflect UV and infra-red rays from the Sun, halving the need for airconditioning and saving energy. That’s good news for the environment.
New solar panels using nanotechnology are becoming more efficient and effective at capturing more of the Sun’s energy, and some solar panels are being developed to be transparent or flexible, becoming more portable, useful in more places, and tougher. Nanotechnology is giving you the opportunity to use clean solar energy wherever you go.
And to get there, you could be driving an electric car powered by nanobatteries. New batteries using nanotechnology have been developed that can recharge in minutes and be recharged over 9000 times, lasting for about 25 years. Compare that to the twoyear lifecycle of a conventional lithium battery.
The future of nanotechnologies
Many social, industrial and environmental benefits are expected to flow from nanotechnology research.
We’ll potentially be able to reduce energy use, make power in environmentally friendly ways, and clean up and save water supplies. Our medical arsenal will get a huge boost.
Nano-manufacturing techniques — building things from the atom up — could start to reduce our reliance on raw materials, and industrial and manufacturing processes will use resources more efficiently and with less waste.
Researchers are also developing high-speed quantum computers that could allow us to do things that are impossible with our current fastest supercomputers, including encryption security unlike anything possible today.
Nanotechnology and health
Anti-cancer ‘nanoships’
Cancer is a high-profile target for medical nanotechnology. One of the latest breakthroughs in United States research is the deployment of ‘nanoships’ containing cancer-fighting drugs through the bloodstream. The ships travel directly to the site of tumours and can be tracked using magnetic resonance imaging (MRI) technology, allowing earlier detection and better treatment.
Electrically conductive scaffolds
CSIRO scientists have created electrically conductive tissue engineering scaffolds designed to support cell growth and new tissue formation. The scaffolds incorporate carbon nanotubes that have been spun into a yarn and knitted into a tubular structure less than four millimetres in diameter. Tested in a laboratory, the scaffolds have been shown to support new cell growth. In the future, these scaffolds may be used to generate replacement body parts such as blood vessels, and regrow severed nerves.
Carbon nanotubes are sub-microscopic, hollow fibres of pure carbon. They can be ‘spun’ into strong yarns to make textiles that conduct heat and electricity.
Repairing spinal injuries
Researchers in the United States have repaired broken spinal cords in mice in only six weeks. The self-assembling nanoparticles, injected into the spinal tissue of paralysed laboratory mice, helped prevent harmful scar tissue from forming and allowed regrowth of damaged nerves.
Crab shells inspire protective nanoparticle
Monash Institute of Pharmaceutical Science researchers have been inspired by chitosan — the structural molecule in crab shells — to develop a nanoparticle that will help people with poor diets or those at risk of developing diabetes or Alzheimer’s disease. Antioxidants, healing substances generated by our body, are needed in greater amounts by some people; but when taken orally, they are easily destroyed by stomach acids and enzymes. Encasing the antioxidants in a chitosan nanoparticle ‘shell’ protects them from attack, allowing them to be absorbed better in the small intestine. In the future, these types of nanoparticle shells could be incorporated into food items, similar to adding microencapsulated omega‑3 fatty acids to bread or milk.
Nanotechnology in food
Nanoparticles can be naturally occurring or can be manufactured. Food and water contain many naturally occurring nanoparticles. For instance, casein, which is a key component of milk, is made from proteins and minerals arranged into natural nano-sized structures that allow for efficient delivery of nutrients to our bodies. Manufactured nanofood products that contain tiny drops of nutrients such as vitamins and minerals are also being developed. These foods aim to increase the amount of nutrients that the body can absorb.
Nanoingredients could be used to create more appealing foods with a longer shelf life, or containing important nutrients that are normally difficult to incorporate into food products. CSIRO researchers are developing nanoingredients, and looking at how to safely make the best use of them to improve our diets and health.
As of March 2009, there are no known food products that specifically make use of manufactured nanoparticles to enhance the product. There are foods with additives that are microor nano-sized, which have been around for many years. All manufactured food sold in Australia must be approved by Food Standards Australia and New Zealand before it is allowed to go to market.
Smart food packaging
Keeping food fresh is a major issue; refrigeration is not accessible everywhere, and also uses a fair amount of power. ‘Smart’ nanopackaging avoids the need for refrigeration. Some use nanoparticles of clay to keep food fresh for months by blocking the passage of oxygen and moisture, slowing the growth of bacteria. Other types of nanopackaging can change colour to alert you if the food is starting to go off, or even self-repair holes and tears.
Invisible sunscreen
Zinc sunscreen is an effective sunblock, but can look thick and unattractive smeared across your nose. ‘Invisible’ sunscreen, made using zinc oxide nanoparticles, is transparent as well as more effective at blocking harmful UV rays. As a bonus, the nanozinc can also be used in paints, plastics and timber products, providing UV protection without destroying a product’s colour or texture.
CSIRO is currently researching potential health-related issues with regard to nano-based sunscreens.
Nanotechnology and water
Safer drinking water
One-sixth of the world’s population — more than one billion people — don’t have access to safe drinking water. Nanotechnology has the potential to help provide safe drinking water supplies.
University of South Australia scientists have discovered a simple way to remove contaminants from water, using particles of pure silica modified with a nanometre-thick coating of active molecules. The particles can effectively remove contaminants such as organic chemicals, proteins, bacteria, viruses and parasites, without the need for additional energy. The particles are recyclable, can be packaged in conventional filter cartridges, and should be commercially available within the next couple of years.
CSIRO research into hand-held environmental sensors will lead to easier ways of detecting sources of water contamination such as disease-causing bacteria. One approach would involve using nanotechnology to construct an array of thousands of different microsensor elements on the surface of a chip. The chip could be used to ‘fingerprint’ environmental samples and help identify the contaminants.
Cleaning up and recycling water
Recycling water is becoming more and more important as a way to conquer Australia’s water shortage. One approach is to recover pure water from industrial and salt water supplies. CSIRO is developing carbon nanotube‑based separation membranes to desalinate and purify these water sources.
A new plastic membrane developed by CSIRO and scientists in Korea and the United States could also help solve the problem of water purification. The membrane mimics the hourglassshaped pores found in plant cell membranes. In plants, these pores allow water molecules to move in and out of cells, while preventing the passage of other molecules such as salt. Creating similar pores in the plastic membrane helps to separate molecules faster, using less energy than other pore shapes.
Biofouling — the growth of plants and animals on underwater surfaces — affects ships and underwater pipes, pumps and cables. In the past, these surfaces were treated with toxic paints. CSIRO and James Cook University researchers are investigating environmentally safe, non-toxic nanomaterial barriers against biofouling.
Nanotechnology and energy
US scientists are developing more efficient and affordable fuel cells for electric cars. Platinum is used to speed up the fuel cell’s chemical reactions, but it degrades quickly. Researchers have added gold to platinum nanoparticles, stabilising the platinum and making it last much longer.
New sources of oil and gas
Researchers from CSIRO, Curtin University of Technology and the University of Western Australia are creating nanosensors to find different hydrocarbons (oils or gases) under the ocean’s surface. The main goal is to find hydrocarbon seeps releasing oil or gas to locate untapped oil or gas deposits beneath the seabed. The nanosensors will also be useful in monitoring marine pollution.
Flexible electronics
Portable electronic devices with a plastic casing that is actually a solar cell will soon make flat batteries a thing of the past. CSIRO scientists are developing flat photovoltaic (solar) cells, using nanotechnology. These could be made into A4 screens that rollout from your mobile phone, letting you watch fullcolour TV or movies, or read newspapers and novels on the go while charging the device.
Spray-on graphene
At the University of Wollongong, scientists are working on how graphene — the individual sheets of one-atom-thick carbon that stack together to form graphite — could save energy. Usually, graphene sheets stick together, making them difficult to use. The researchers have worked out how to keep nanosheets of graphene separated, in a low-cost approach that allows graphene to be sprayed or filtered on a large scale to produce electrically conductive films. Such a product could be used to make transparent electrodes for solar cells and new electrodes for batteries.
Any advances in energy efficiency, or in renewable energy, will also help to reduce greenhouse gas emissions, which in turn will help lessen the effects of climate change.
Multipurpose nanocrystals
The University of Queensland’s research into nanocrystals will have many benefits. The researchers have grown single titanium dioxide nanocrystals that have a large reactive surface, which means that they can carry out chemical reactions quickly and efficiently. The crystals are showing promise for use in cutting the cost of solar cell manufacture and producing hydrogen from splitting water molecules. Plus, they can break down pollution in water and air. Layers of the crystals should be available to paint on windows or walls to purify the air in a room within the next five years.
Understanding the safe use of nanotechnology
Like all technologies, nanotechnology has both benefits and risks. The Australian Government’s Health, Safety and the Environment (HSE) nanosafety working group liaises between all relevant government agencies to ensure that safety issues in relation to nanotechnology and its many applications are being addressed. These agencies are increasing their own knowledge of nanomaterials and their application through a range of sources. The Government is also working with overseas governments and international organisations to keep on top of any emerging health, safety and environmental issues arising from nanotechnology. When required, risk management strategies are then adjusted for nanotechnology-related research, manufacturing and consumer use, as well as community and environmental impact. It is estimated that approximately five per cent of currently manufactured nanoparticles may be of concern for safety reasons.
Contributing to this work is the nanosafety research in CSIRO’s Future Manufacturing Flagship, which provides scientific information on the effects that some nanomaterials may have on human health and environment. The research includes finding out if or when humans and the environment may be at risk from exposure; monitoring workplace exposure to nanoparticles and the effect it might have on health; and determining what happens when nanoparticles are released into the environment.
Predicting the fate of nanoparticles
The use of nanoparticles in research is becoming increasingly widespread. CSIRO researchers are looking at what could happen when nanoparticles end up in waterways and landfill. By building computer models, the behaviour of nanoparticles can be predicted before they make their way into the environment.
Fonte: Australian Government - Department of Industry, Innovation, Science, Research and Tertiary Education
