Small scale... Huge potential

INNOVATIONS OF 2007: Forty-eight years ago this month, US physicist, future Nobel laureate and mild eccentric Richard Feynman delivered a talk to an American Physical Society meeting at California Institute of Technology called 'There's Plenty of Room at the Bottom'. In it he foresaw the potential of working on a tiny scale and directly manipulating atoms, and he inspired decades of research.

Nearly half a century on, the burgeoning field of nanotechnology now engineers substances at the scale of billionths of metres and provides a common playground for chemists, physists, engineers and biologists to mingle.

And with those interactions comes a flood of innovation. We can now envisage 'living computers' made from biological materials, scientists are aiming to store data on single atoms, and researchers are even developing 'Lego'-like molecular blocks that mimic shapes found in our body's proteins and link together build tiny, complex machines.

Choosing one or two examples from an area os such wealth is a challenge, but California-based company Nanosolar has recently come up with a new slant on converting solar energy to electricity that demonstrates how mould-breaking nanotechnology can be.

In a conventional solar cell the light goes through a band gap, hits something and knocks out an electron, which is where the energy comes from for electricity, explains physicist Dr Mike Hopkins, who is theme leader for sustainable energy at Dublin City University.

Nanosolar has developed a nanoparticle approach that puts solar-converting nanostructures into a solution. And, as with so many substances at the nano level, the handling properties of these nanostructures are very different to their larger cousins. "The particles themselves are a combination of metals and other particles. It works in a similar way to a solar cell but because it's nanoparticles the physics is much more complex and they can produce a much thinner film," explains Hopkins.

Their innovative nanoparticles can be sprayed in a thin film onto building materials like roofing tiles, explains Hopkins, and happily sit there converting solar energy. Wires conduct the energy from the roofing tiles back to an AC/DC converter and the electricity can be loaded onto the grid.

Their spray-on solar-harvesting film, which will hit the market in coming months, rivals the more expensive solid-state cell for energy conversion (about 20 per cent) but slashes the cost of electricity production by a factor of ten - from $3 to 30 cent per watt. "At the moment using a conventional solar cell would be more expensive than buying your electricity from the grid or other sources like wave or wind," says Hopkins. But the nano approach suddenly makes solar more cost-effective. "Even in a latitude like Ireland it would be cheaper than grid electricity."

Nanotech is also putting diagnostics into the palms of our hands, with tiny integrated devices for screening drops of blood or saliva for DNA markers or for specific diseases. The idea has been around for while, but ST Microelectronics has now put a 'lab on a chip' on the market. The device, which is about an inch long, uses microfluidic channels to guide the sample fluid to a chip that's loaded with the relevant test, and results are pretty instantaneous, explains Hopkins.

"There's a huge array of tests being developed now to go with this technology. You can put a battery of tests into a disposable unit and it's very quick," he says.

Those tests could range from notifiable public-health threats at airports like avian flu, right through to more routine diagnostics in the clinic. "If someone looked off colour in an airport you could test them, or you could use the same technology to do immediate tests in a doctor's surgery," says Hopkins.

It's an example of how the semi-conductor and computer industries, which have been playing at the nano level for years, are increasingly converging with other disciplines, he adds. "Up to now we have been developing chips that think, and now we are adding senses to them, the capability to sense things and expand in new dimensions. You have the electronics industry being able to interact with the chemical and biological."

"Sustainable and save-the-planet technologies are now going to get most of their innovations from the nanotechnology world"

Nanotechnology is going clean and green for 2008. Environmentalists have sometimes feared the nano approach of engineering materials at the tiny scale of billionths of metres. But now it looks as though the lightweight materials and chemical quirks that nanotech enables could make strides towards saving the planet.

The focus is particularly on the area of "cleantech" or clean technologies that improve performance while minimising environmental impact. "Sustainable and save-the-planet technologies are now going to get most of their innovations from the nanotechnology world," says Prof. Jim McLaughlin, director of the Nanotechnology and Integrated Bioengineering Centre at the University of Ulster.

Ongoing developments include lighteweight automotive and aerospace nanomaterials, controlling the nanochemistry of storing and releasing hydrogen from fuel cells and using nanoencapsulation to control the release of enzymes in land remediation, he notes.

"What you will have heard of is sustainable energy and the environment and people find those topics too big to tackle. But if you start to talk about cleantech and what can be done with nanomaterials then people start to understand it better and it gives a bit more focus," says Prof. McLaughlin.

"The US investment world believes you will get very quick returns from the cleantech environment, and we have seen the pronounced link between nano and cleantech. It hasn't hit Europe as much, but the predictions are that next year we will hear a lot more about cleantech."