Nanoscience provides a powerful tool kit for scientists; it is now used to solve problems in everything from medicine and chemical engineering to space science.
It began with a challenge from a great physicist. In 1959, Nobel laureate Richard Feynman gave a lecture titled “There's plenty of room at the bottom,” in which he posed a question: “Computing machines are very large, they fill rooms,” he said. “Why can't we make them very small, make them of little wires, little elements — and by little, I mean little.” His big idea was to miniaturise existing objects. They could be made from the ground up by manipulating individual atoms or molecules. More than half a century later, he might not recognise how his ideas have been transformed into a powerful tool kit for scientists, now called nanotechnology.
“In the broadest sense, we're talking a billionth of a metre [a nanometre] and typically technologies that are between 10 and 100nm,” says Keith Dingwall, an analyst at the U.K. Institute of Nanotechnology. “What we're talking about here is manipulating materials on a molecular scale.” The field goes beyond Feynman's aim to make things smaller. Nanoscience ideas are used in everything from medicine and chemical engineering to space science and telecommunications. “I wouldn't call it a discipline, I'd call it a tool kit,” says Gabriel Aeppli, professor of physics at the London Centre for Nanotechnology. “It's used in the micro-electronics sector but also in medical diagnostics — pregnancy tests use gold nanoparticles. It's a tool kit that people to use to solve problems in a variety of areas without any regard for its label.” This means there is no such thing as a typical nanoscience lab. One place with the prefix “nano” on its doors might see scientists building entirely new materials. Another might be focused on building a solar cell inspired by a natural leaf. And a third might be moving atoms on a surface to see what strange things happen at the nanoscale.
The problems; carbon nanotubes
With new technology comes new responsibility, and nanoscientists say they are aware of the problems associated with the manipulation of such tiny things. “As societies have become wealthier, they have traditionally become more risk-averse but they've also become rich enough to be able to take steps to reduce the risks of exploring new chemistry,” says Aeppli. “My sense is that we simply have to treat all of the things that haven't been tested yet in the same way that we deal with anything that a synthetic chemist might produce.” Take carbon nanotubes. These tiny tubes are made of carbon atoms and are incredibly strong and conductive but, because of their shape, they could potentially be harmful. Some early research on lab mice suggested carbon nanotubes could behave like asbestos particles if inhaled. As nanotubes become incorporated into more everyday materials, what happens if they are released into the environment? The answer will need rigorous testing and characterisation of nanosized particles or brand new materials. But some argue that too much caution can hinder innovation. Pre-empting (and trying to preregulate) technology that does not yet exist is not a good idea, says Ineke Malsch, director of Malsch TechnoValuation and the author of an EU Observatory Nano report on the ethics of nanotechnology.
Applications in health
Most current applications of nanotechnologies could be covered by pre-existing legislation in areas such as chemical or drug safety. Malsch says the key issues in the long-term centre on the way nanoscience will interact with our biology, up to and including human enhancement. “What would be the boundary between nanotechnology in medical or biological applications or therapy, in healing sick people — when does it get to be improving people, making healthy people better?” Malsch adds: “At the moment politicians and policymakers don't really have a clue how to regulate or what would be applicable norms and standards and ethical values to apply to these issues. Fortunately, there is still time for that because the technology is not ready yet.” Medicine is an important area. Alfred Cuschieri, director of the Institute of Medical Science and Technology in Dundee and St Andrew's Universities, has worked on a novel way to treat people using carbon nanotubes within NINIVE, a European nanotechnology research project. Each nanotube carries a pharmaceutical payload on its surface and is able to slip into the body's cells — cancerous or otherwise — much like a nanosized needle. When the nanotubes get to their target, a pulse of microwaves from the outside makes them shed their pharmaceutical loads inside the cells. “My guess is that targeted drug delivery systems based on carbon nanotubes as vectors will probably start to be tested in early clinical phase—one studies in about three to four years' time,” says Cuschieri.
He adds: “Following on from the project, we've found out that these carbon nanotubes, if they're constructed in a specific way, can actually stimulate nerve cells. This led to a subsequent project — if you have patients with Parkinson's disease, for example, and you put some of these special nanotubes in, you can use the same energy used in cellphones to stimulate the cells.” Far less complex products are already available for your shopping basket. Nanoparticles of varying types are used in sunscreens and car paint, they are used to catalyse chemical reactions in factories and used in every modern electronic device. “In the electronics industry, people have been manipulating stuff on a nano scale for a long time but it's not referred to as such,” says Dingwall. “Gold particles are being combined with things like carbon nanotubes in the fabrication of memory chips.” Humans have (without knowing it) used the fruits of nanotechnology for thousands of years, says Dingwall, but the technology to manipulate it has only been available in the past few decades. Expect great (but very small) things. —© Guardian Newspapers Limited, 2011