Nanotechnology – taking it to the people

Key text

Unlike information technology – where it’s easy to spot new products like computers, iPods or mobiles – consumers won’t be buying ‘nanotechnology products’ so much as products developed or enhanced through nanotechnology.

Just because nanotechnology may not always be easy to spot, that doesn’t mean that it won’t be making big impacts on the world in the next decade.

How might nanotechnology impact on your world in the next 10 to 20 years? Let's consider the two biggest investments made by most families – the house and car.

The nanohouse

Related site: Nanohouse Describes an ultra-energy efficient house that exploits the new materials being developed by nanotechnology. (Institute for Nanoscale Technology, Australia)

A house making use of products emerging from nanotechnology would be extremely energy-efficient, due to radiative cooling paint on its outer surface. It would have self-cleaning surfaces, cold lighting systems and dye-sensitised solar cells to generate electricity. It would be easy to assemble and take apart, cheap to run and comfortable to live in.

Scientists at the CSIRO and the University of Technology Sydney have developed a model nanohouse demonstrating these features. The nanohouse shows how new materials, products and processes emerging from nanotechnology research and development can be used in the buildings we live and work in.

The nanocar

The nanocar would likely be made of superlight, superstrong, recyclable fibre composites. It would run on hydrogen and atmospheric oxygen combined in fuel cells to produce electricity. The fuel cells and fibre composites could both be products of nanotechnology and advanced materials research in the decades ahead.

The hydrogen that powers the nanocar is a very attractive transport fuel because it is abundant, renewable and its consumption in fuel cells produces no greenhouse emissions. But hydrogen, being a volatile gas, does come with some safety problems. Gas cylinders and hydrogen liquid in cryogenic containers are a hazard in the event of an accident. One way around this hazard would be to store the gas in fuel tanks consisting of arrays of carbon nanotubes. Because of their structure and size, the nanotubes have the ability to absorb hydrogen gas in large quantities. The hydrogen can then be released when required by mild heating.

Related site: Rice scientists build world's first single-molecule car Describes the use of nanotechnology to build a nanocar. (Rice University, USA)

On a different scale, scientists have created the world's smallest working car – only one molecule big and complete with a chassis, axles and wheels.

The products showcased in the nanohouse and nanocar come from different areas of nanotechnology, but what is nanotechnology?

What is nanotechnology?

Nanotechnology is engineering at the molecular or atomic level. It’s about manipulating matter over the scale of 1 to 100 nanometres. A nanometre is one-millionth of a millimetre. Nanoscience is the knowledge of how to manipulate and characterise matter at the nanoscale.

Related site: Nanoscience – working small, thinking big Provides an introduction to nanoscience and working at the nanoscale. (Nova: Science in the news, Australian Academy of Science)

Nanoscience and nanotechnology overlap in scope but they are different. Without nanoscience, nanotechnology would not be possible. However, without economic returns and improvements derived from nanotechnology, there would be no further investment in nanoscience.

New nanotechnology developments are announced every day. By examining the three areas of nanopowders, nanotubes and nanomembranes it’s easy to appreciate how nanotechnology might be changing the world around us.

Nanopowders

Nanopowders contain particles that are under 100 nanometers in size. Particles of this size are invisible to the naked eye because they are smaller than the wavelength of visible light. Such small particles also have an enormous surface area to volume ratio (Box 1: Putting nanopowders to work).

The addition of nanoparticles to existing materials is creating a range of new products and applications including:

• transparent plastics that are resistant to abrasion, conductivity or UV light;
• synthetic bone and bone cement;
• drugs that target specific cells with improved solubility, greater efficacy and fewer side effects; and
• catalysts to clean up car exhausts.

Improved catalysts will enhance existing technologies to such an extent that whole new markets might take off. For example, nanostructured catalysts are likely to make fuel cells a commercial reality, which could transform industries that generate and distribute power.

Nanotubes

Nanotubes are hollow cylinders of atoms measuring only nanometres in thickness. Scientists first discovered nanotubes made of carbon atoms, but recently they have discovered how to make tubes from other elements too.

Products that include nanotubes already exist. Samsung has produced a prototype version of a flat panel display screen where electrons are fired at a screen from the tips of nanotubes. And scientists from CSIRO have discovered a way to spin carbon nanotubes into yarn.

Related site: IPE nanotube primer Provides information on the structure, properties and applications of nanotubes. (Institut de Physique des Nanostructures, Switzerland)

The size and structure of nanotubes give them a range of unique physical, electrical and chemical properties. It's believed they might provide us with a new generation of high-strength, light-weight materials. They could serve as 'fountain pens' that deposit atoms instead of ink. The electrical properties of nanotubes mean they'd make great nano circuits. They may be engineered to build engines with gears only two nanometres across.

Nanomembranes

Nanomembranes – filters that have the ability to efficiently separate molecules in liquids or gases – have many uses.

The idea of filtering molecules with nanoscale membranes comes from living cells that use membranes to remove salt from blood, and to transfer oxygen and carbon dioxide. Large membrane surface areas reduce the energy requirement for the transport of molecules. Nanotechnologists aim to achieve the same filtering effect used by nature with nanomembranes that filter molecules of different sizes.

Scientists at the CSIRO have developed a membrane that uses organic polymers in a mesh of silica nanoparticles. The membrane contains nanometer-sized holes and can be used to separate large and small molecules. This new membrane may soon be used to purify medicines, make better fuels and to desalinate sea water. Researchers in the Unites States and Israel are looking at nanomembranes that clean polluted water by sifting out bacteria, viruses, heavy metals and organic material.

Nanomembranes are also being developed to separate carbon dioxide and hydrogen from flue gases produced when burning fossil fuels to generate electricity. The carbon dioxide can be captured – preventing it from being released into the atmosphere – and a pure stream of hydrogen can be obtained for use as an additional source of energy. Other types of membranes can selectively block or release gases to protect food from spoilage.

Nanopowders, nanotubes and nanomembranes are just a subset of what nanotechnology encompasses but they give you a taste of the enormous potential of this developing field.

A disruptive technology

Nanotechnology is rapidly becoming ubiquitous and all pervasive in our modern world, with potential to transform the way we live.

Because of its enormous potential for change, nanotechnology is often referred to as a disruptive technology. This is not to suggest that nanotechnology is bad – rather it is expected that the increasing uptake of nanotechnology will disrupt existing enterprises and ways of doing things. For example the mining industry might be able extract minerals using bio-leaching without disturbing the landscape. The food industry might be able to eliminate contamination with tailor-made polymer protective coatings and wraps. Solar cell paints might transform energy generation while new biomaterials may revolutionise tissue and organ replacement. New high strength, low-weight building materials may radically alter the way we design and build houses, while advances in integrated built-in computer sensors and systems might change the way we work, learn and play.

While it's easy to see how we can benefit from enhanced processes and products created by nanotechnology, it's just as important that the community also explore the possible social, ethical and safety concerns connected to the widespread use of these new technologies (Box 2: Beyond the grey goo).

While no-one knows what tomorrow may bring, it seems likely that nanotechnology will be shaping a large part of it.

Related Nova topics:

Nanoscience – working small, thinking big

Buckyballs – a new sphere of science

Box 1: Putting nanopowders to work

One of the first Australian companies to operate in the nanotechnology sector was Advanced Powder Technology (now called Advanced Nanotechnology Limited). The company was established in 1997 to commercialise research carried out at the University of Western Australia on a process for manufacturing nanoparticles. The process is known as mechanochemical processing and involves grinding down powders in a ball mill and then heat treating them to create a wide range of high quality nanopowders. These powders are now being used in a variety of innovative products. These include:

• ZinClear® – a transparent SPF 30+ sunscreen containing only zinc oxide as the UV absorber. Zinc oxide is considered to be the safest UV absorber that one can use on the skin and this product uses no other chemical UV absorbers.
• NanoZ®  – a transparent UV blocking zinc oxide dispersion for the protection of timber - a similar concept to Zinclear® but applied to wood. Zinc oxide nanoparticles do not degrade in the sun so this coat provides long-lasting transparency and protection from UV damage.
• Alusion®  – consists of platelets of aluminium oxide used in cosmetics to create soft focus effects and enhance the feel and adherence of colour cosmetics. It's claimed to work wonders at masking the effects of ageing.
• Cercat™ - cerium oxide nanoparticle dispersions, a key component in Envirox™, a diesel fuel additive improves fuel consumption and also reduces harmful exhaust emissions.

Related site

• Products (Antaria: An Advanced Materials World, Australia)

Box 2: Beyond the grey goo

In years gone by it has been suggested that nanotechnology might be a Pandora's Box and that the creation of self-replicating nanomachines would lead to a grey goo taking over the world. As the realities of nanotechnology have begun to take form, the 'grey goo' scenario has been increasingly dismissed as speculative rubbish, though there remains significant fear in many quarters that nanotechnology may still contain a hidden sting in the tail.

There is a growing concern, for example, about the health risks posed by some nanoparticles. Experimental studies in rats have shown that at equivalent mass doses, insoluble ultrafine particles (smaller than 100 nanometers) are more potent than large particles of similar composition in causing pulmonary inflammation and lung tumors. Whether these effects would occur in exposed workers is not known.

A 2004 report by the Royal Society and the Royal Academy of Engineering in the United Kingdom concluded that many applications of nanotechnologies pose no new health or safety risks. However, some nanoparticles that are freely mobile may have the potential for negative health and environmental impacts because of their size or particular chemical properties. It is reasonable to assume that at least some manufactured nanoparticles may be more toxic per unit of mass than the bulk material. The report recommended that in the specific case of free nanoparticles and free nanotubes, existing regulatory frameworks need to be modified and that until more is known about the environmental impacts of nanoparticles and nanotubes, release into the environment should be avoided.

Social and ethical concerns about nanotechnology

As with the spread of any powerful new technology, there are likely to be a range of negative as well as positive outcomes associated with nanotechnology. While nanotechnology may provide us with clean water and cheaper medicines, these benefits might only accrue in the developed world with the developing world missing out. Just as there is a growing 'digital divide' between countries with information technology skills and developing nations that lack these skills, so too there is potential of a growing 'nano divide'.

Smaller sensors, more effective electronics and computers are expected outcomes of nanotechnology. They will improve our capacity to monitor society and keep track of people considered a risk to the community. This provides greater security and addresses potential problems before they become a threat, but it also makes it easier for governments to enforce control and has the potential to threaten our privacy.

Nanotechnology also promises improved drugs, drug delivery and disease diagnosis and treatment. Each new drug, however, also brings its own range of risks, which may not be realised for many years. Improved disease diagnosis might also have privacy implications as it becomes possible to screen whole populations for specific problems.

Many issues that relate to the safe and ethical use of nanotechnology overlap with other areas of technology such as biotechnology and information technology. In a sense, it's not the technology that is in question but the control over its use and the equitable distribution of benefits.

Related sites

• Nanoscience and nanotechnologies: Opportunities and uncertainties (The Royal Society and Royal Academy of Engineering, UK)

• What is nanotechnology and what can it do? (AZoNano.com)

• The Ethics of Nanotechnology (Nanotechnology Now)

• Nanodevelopment (Higher Education and Research Opportunities, UK)

Activities

• AccessNano (Australian Government Department of Innovation, Industry, Science and Research)
  Provides a series of 13 teaching resources on nanotechnology. These include PowerPoint presentations, experiments, activities, animations and links to interactive websites.

• Molecular expressions (Florida State University, USA)
  • Perspectives: Powers of 10 – students draw the same object at different magnifications.
  • Virtual scanning electron microscopy – an interactive Java tutorial that allows students to view specimens (eg, grasshopper, jellyfish) at different magnifications with a virtual scanning electron microscope.
  • Secret worlds: The universe within – provides a series of pictures (from the Milky Way to electrons), each of which is an image of something that is 10 times smaller than the one before it.

• Interactive Nano-visualization in Science and Engineering Education (USA)
  • List of modules – a number of web-based educational modules about materials. 'Size and scale' includes topics such as 'Defining dimensions' and 'Does size matter?'  with links to relevant online activities.
  • Scanning probe microscope – introduces the theory and application of these microscopes as tools of nanotechnology. The module 'Is smaller better?' has information that is relevant to nanoscience, but there are no online activities.

• Sciencemax (Reed International Books, Australia)
  • Small wonders – this activity is on the last page of this PDF file and asks students to design a prototype of a nanomachine. There are also a number of other tasks asking students to find out more about different aspects of nanotechnology.

• Discovery School (USA)
  • Future body – students investigate how electrical signals are used in the human nervous system. They look at how computer chips or electrodes might be used to repair or augment the system.

• Nanobiotechnology Center (Cornell University, USA)
  • Nanosmores and photolithography – students make an edible, layered biscuit to represent the process used to create a patterned silicon wafer using a substrate and a photosensitive chemical.

• Exploring the nanoworld (Materials Research Science and Engineering Center on Nanostructured Materials and Interfaces, University of Wisconsin, USA)
  • Structures at the nanoscale – shows how students can use LEGO^® bricks to demonstrate the nanostructure of solids.
  • Self-assembly: Building structures at the nanoscale – students make a square pattern of magnetic LEGO^® bricks using a 'top-down' and a 'self-assembly' approach.
  • Educator resources – provides a variety of activities related to nanoscale technology. The activities are presented under three headings – Nanoscale activities, Applications activities, and Societal implications activities.
  • Interdisciplinary education group – provides a variety of resources in addition to those mentioned above (eg, 'Nanoworld cineplex of movies' and 'Nanoscale video lab manual').

• NanoSense (USA)
  • Size matters – an introduction to nanoscience, including activities on size and scale, unique properties at the nanoscale, nanofabrication techniques and applications of nanoscience. Other lessons are under development.

• NanoSense (USA)
  • Clear sunscreen: how light interacts with matter – explores issues related to size and scale, specifically the effect of the size of nanopowders on the interactions of energy and matter.

Further reading

• What colour is gold (by Paul Mulvaney)
• Pollution's sweet solution (by Michael Moylan)
• Nanoengineering smart particles (by Frank Caruso)
• Manipulating viruses to grow semiconductors (by Angela Belcher)
• Thermodynamic limits to nanomachines (by Denis Evans)
• Nanotechnology raises big issues (by Vijoleta Braach-Maksvytis)

• From Rusal with love (by Pavel Ulianov)
• Nano work for cement giants
• How nanomaterials can benefit healthcare (by Jim McLaughlin)
• Powering ahead (by Matt Harris)
• Measure for measure
• Printing panache (by Paul Butler)
• Nanotechnology ethics (by Geoffrey Hunt)
• Holding it together (by Michael Forrest)

• Down to the nearest billionth
  
• Treating and healing on three fronts
  
• The miracle and the infinite
  
• Toxicity under nano-surveillance

May 2009, pages 60-65
Powering nanorobots (by Thomas E. Mallouk and Ayusman Sen)
Describes research into ways of controlling nanomachine movement.

Useful sites

The Basics of Nanotechnology (Oxford University, UK)

An interactive site that provides an overview of nanotechnology, its history and likely impact.
http://www.begbroke.ox.ac.uk/nanotech/interface.html

Nanotechnology: Enabling technologies for Australian innovative industries (Australian Government Department of Science, Education and Training)

A report prepared by the Prime Minister’s Science, Engineering and Innovation Council on nanotechnology.
http://www.dest.gov.au/sectors/science_innovation/publications_resources/profiles/
nanotechnology_enabling_innovative_industries.htm

Australian Trade Commission

• Nanotechnology
  Provides links to a number of reports on the Australian nanotechnology industry and companies.
  http://www.austrade.com/Nanotechnology/default.aspx

Center for nanotechnology (National Aeronautics and Space Administration, USA)

Describes nanotechnology applications being developed for use in space.
http://www.ipt.arc.nasa.gov/index.html

How Stuff Works (USA)

• How nanotechnology works
  http://science.howstuffworks.com/nanotechnology.htm

• How DNA computers will work
  http://computer.howstuffworks.com/dna-computer.htm

Some examples of how nanotechnology impacts our lives now (Nanotechnology Now)

Gives examples of nanocomposites, nanocrystals, nanoparticles and other applications of nanotechnology.
http://www.nanotech-now.com/current-uses.htm

Nanoscience: Articles (Wellcome Trust, UK)

Provides a series of questions and answers about nanotechnology.
http://www.wellcome.ac.uk/Professional-resources/Education-resources/Big-Picture/Nanoscience/Articles/index.htm

Azonano.com

• Drug delivery systems – markets and applications for nanotechnology-derived drug delivery systems
  http://www.azonano.com/details.asp?ArticleID=1078

• Commercial nanotechnology applications to help the environment and save energy
  http://www.azonano.com/details.asp?ArticleID=1058

• Fuel cell, energy storage and solar energy applications for nanomaterials and nanoparticles
  http://www.azonano.com/details.asp?ArticleID=1339

• Molecular electronics and quantum dots – properties and future applications
  http://www.azonano.com/details.asp?ArticleID=564

• Buckytubes: Introduction and basic facts
  Provides an introduction to bucky tubes.
  http://www.azom.com/details.asp?ArticleID=1295

• Buckytubes: Properties
  Provides information on the properties of buckytubes.
  http://www.azom.com/details.asp?ArticleID=1294

• Buckytubes: Applications
  Provides information on some of the applications for buckytubes.
  http://www.azom.com/details.asp?ArticleID=1293

The lotus effect (International Space University, France)

Describes the lotus effect, which is the inspiration behind self-cleaning surfaces.
http://lotus-shower.isunet.edu/the_lotus_effect.htm

Nanotechnology to create green hydrogen? (Environment Society of Australia)

Reports on the development by the Hydrogen Solar company of a nano-crystalline material that improves the production of hydrogen from water using solar energy.
http://enviro.org.au/hydrogen.asp

Australian Broadcasting Corporation

• Growing concern over nano-tech (Future tense, 9 April 2009)Calls for greater regulation of nanotechnology

• AccessNano (Australian Government Department of Innovation, Industry, Science and Research)
  Provides a series of 13 teaching resources on nanotechnology. These include PowerPoint presentations, experiments, activities, animations and links to interactive websites.
  http://www.accessnano.org/teaching-modules
  

• Growing concern over nano-tech (Future Tense, 9 April 2009)
  Discusses concern over the lack of regulation of nanotechnology.
  http://www.abc.net.au/rn/futuretense/stories/2009/2536769.htm

• Revolutionary fibres using nanotechnology (The Science Show, 19 July 2008)
  Outlines Australian research into materials produced using nanotechnology.
  http://www.abc.net.au/rn/scienceshow/stories/2008/2307917.htm

• Nanotech regulation under the spotlight (News in Science, 11 July 2008)
  Reports on uncertainties in the regulation of nanotechnology in Australia.
  http://www.abc.net.au/science/articles/2008/07/11/2301399.htm?site=science&topic=latest

• Nanoparticles in sunscreen (The Science Show, 15 October 2005)
  Discusses the use of nanoparticles in sunscreens and their application in the removal of certain skin tumours.
  http://www.abc.net.au/rn/science/ss/stories/s1480390.htm

• Nanotechnology: The science of the future (The Science Show, 19 March 2005)
  Comments on the interest among young people in the undergraduate degree courses in nanotechnology.
  http://www.abc.net.au/rn/science/ss/stories/s1324770.htm

• The challenges facing nanotechnology (Ockham’s Razor, 20 February 2005)
  Examines the hurdles nanotechnology must overcome before it becomes a society-transforming revolution.
  http://www.abc.net.au/rn/science/ockham/stories/s1304778.htm

Glossary

atom. The fundamental unit of all matter consisting of a nucleus of protons and neutrons surrounded by orbiting electrons (or in the case of hydrogen, just one electron). For more information see Back to Basics: Atoms and molecules (Australian Academy of Science).

catalyst. A substance that increases the rate of a chemical reaction without actually undergoing any change itself.

composites. Composite materials are formed by combining two or more materials that have quite different properties. The different materials work together to give the composite unique properties, but within the composite you can easily tell the different materials apart – they do not dissolve or blend into each other. One material (the matrix or binder) surrounds and binds together a cluster of fibres or fragments of a much stronger material (the reinforcement). For more information see our Nova topic Putting it together – the science and technology of composite materials.

electrical conductivity. When a voltage is applied across a substance, an electric current will only flow if the substance conducts electricity. When salts dissolve in water, ions are formed and the solution (the electrolyte) will conduct electricity. As a general rule, the higher the concentration of ions in solution (ie, the higher the salt concentration) the better the solution conducts electricity; in other words, its electrical conductivity increases. Electrical conductivity is often expressed in units such as deciSeimens per metre (dS/m). Rain water, for example, has a conductivity of 0.02-0.05 dS/m, while sea water has a conductivity of 50-60 dS/m.

fuel cell. A device that converts energy from chemical reactions directly into electrical energy. The simplest fuel cell 'burns' hydrogen in a flameless chemical reaction to produce electricity. In order to 'burn' the hydrogen a fuel cell needs a source of oxygen and this is usually obtained from air. The only by-product from this type of fuel cell is water. For more information about fuel cells see our Nova topic Fuelling the 21st century.

molecule. The smallest unit of a chemical compound that can exist. It consists of two or more atoms held together by chemical bonds. Molecules can vary greatly in size and complexity.

nanometre (nm). One-millionth of a millimetre (or one-billionth of a metre). This is the scale at which we measure atoms and the molecules they make. For example, ten hydrogen atoms laid side by side measure a nanometre across and a pin head is around a million nanometres wide. The 'machines' inside our cells and the molecular constructions they put together are measured in nanometres.

nanopowders. Nano-sized particles exhibit a range of physical, chemical and biological properties that are quite different to bulk materials of the same substance. Industry is now making use of these changed properties to enhance the functionality of many products.

nanotubes. Extremely small tubes made from atoms such as carbon nanotubes or boron nitride nanotubes. For more information see IPE nanotube primer (Institut de Physique des Nanostructures, Switzerland).

solar cells. Convert light energy into electrical energy. Also known as photovoltaic cells. A solar cell is made of thin wafers of two slightly different types of silicon. One, doped with tiny quantities of boron, is called P-type (P for positive) and contains positively charged 'holes', which are missing electrons. The other type of silicon is doped with small amounts of phosphorus and is called N-type (N for negative). It contains extra electrons. Putting these two thin P and N materials together produces a junction (often refered to as P-N junction) which, when exposed to light, will produce a movement of electrons – and that constitutes an electric current. Though most widely used solar cells are made of silicon, other materials could also be used to create P-N junctions.

ultraviolet (UV). A form of electromagnetic radiation. UV radiation has shorter wavelengths than visible light and it therefore carries more energy. It is divided into three broad categories: A, B and C. UV-A has the longest wavelength and is the least damaging form, although sufficient exposure will cause sunburn. UV-B damages proteins in unprotected organisms and can cause cancer, while UV-C is extremely dangerous because it can cause mutations in DNA.

visible light. The wavelength of visible light ranges from 400 to 700 nanometres while the wavelength of X-rays ranges from about 0.01 to 10 nanometres. The relatively long wavelength of visible light sets the limit of how small an image it can produce. For more information see Electromagnetic radiation (Back to basics, Australian Academy of Science).

wavelength. The distance between two adjacent wave crests. Visible light and X-rays are both electromagnetic waves and differ from each other only in the length of the wave. The wavelength of visible light ranges from 400 to 700 nanometres while the wavelength of X-rays ranges from about 0.01 to 10 nanometres. The relatively long wavelength of visible light sets the limit of how small an image it can produce. For more information see Electromagnetic radiation (Back to basics, Australian Academy of Science).