To see the world in a grain of sand

PUBLISHED : Sunday, 13 May, 2012, 12:00am
UPDATED : Sunday, 13 May, 2012, 12:00am


Ever wonder why it's so hard to swat a fly? It's because that pesky little insect has better flight manoeuvrability than any human or any machine that humans have yet devised.

The common housefly leaves the most advanced jet fighter in the dust: it turns right angles in one twentieth of a second, it reaches top speed in two-hundredths of a second and its wings flap over 200 times a second (hence the buzzing sound). The fly's flight commands originate from 100,000 neurons in its brain that can be seen only under an extremely advanced microscope.

The fly's brain and countless other complex systems in nature are invisible to the naked eye. They operate below the threshold of human vision, at the level of atoms, molecules, proteins and cells - or the nanoscale, which is a thousand times smaller than the microscopic scale and a billion times smaller than the metric scale.

But it's only in the last 30 years, with the development of electron microscopes, which use a beam of electrons to see things too small to be seen using light, that scientists have been able to observe matter at the nanoscale. By zooming into it, they have been able to study how atoms and molecules make things happen, leading to the new field of nanoscience. Advanced nanoscopic microscopes also have a tiny probe that can move atoms and molecules around and rearrange them. This amazing capability has given rise to the new frontier of nanotechnology, one of the most exciting in science and technology today.

Nanotechnology can be defined as the creation or manipulation of engineering systems of between one and 100 nanometres (a nanometre is one billionth of a metre). To put that in perspective, the diameter of an atom is between 0.1 to 0.5 nanometres, the diameter of a human hair about 1,000 nanometres. So nanotechnology works with devices that range in size from two atoms to one-tenth of a human hair.

What's the point of doing things on such an incredibly small scale? At this scale, many substances take on different physical and chemical properties that can be used to make highly innovative products - from nano-materials that are stronger, more durable or more dirt-resistant than anything we have today, to nanobots that can be sent into hazardous environments to clean up nuclear waste.

Scientists research the nano-world in different ways. For example, biologists investigate nano-engineering in natural organisms and seek to produce technical equivalents for it. This area of research has been dubbed 'bio-inspiration'. The great American physicist Richard Feynman was the first to observe, in 1959, that enormous amounts of information and sophisticated engineering are carried out in exceedingly small spaces in biological systems.

Among innumerable examples of biological systems employing nanotechnologies that have evolved over millions of years are: nanoscopic tunnels in the male silk moth's antenna, which can detect a single molecule of the sex pheromones emitted by a female moth up to 4.5 kilometres away; a gecko's toepad, which has billions of bristles ending in spatulas about 200 nanometres wide that make contact with a surface, allowing it to scuttle upside down on the ceiling; and the lotus leaf, which has a rough surface made up of many tiny bumps that repel water and keep it clean.

Understanding the materials and engineering of such systems in nature has enabled scientists to develop bio-inspired nanotechnologies for human use. For example, discovery of the lotus' self-cleaning powers has led to a new class of self-cleaning glass and paint. Engineers are studying the fly's flight-control scheme to learn lessons for the design of micro-air-vehicles that can discreetly enter and scout buildings, locate people in confined spaces or detect bombs.

While biologists look for inspiration in nature, material scientists and physicists are building nanostructures from the bottom up, moving and assembling individual atoms and molecules one at a time, much like a wall is built brick by brick. With atomic precision, they are building machines just nanometres wide - motors, gears, robot arms, even whole computers.

This may seem far-fetched. But Gordon Moore, a co-founder of Intel, predicted in 1965 that advances in solid-state physics and materials would pack more and more transistors into integrated circuits, doubling computing power every six months, resulting in smaller, faster and cheaper computers. This ever-increasing computing power, now known as Moore's Law, will continue with nanotechnology.

At the Lawrence Berkeley Laboratory in Berkeley, California, physicists are working on computer chips so small and powerful that four wine bottles full of such chips will, they claim, store all the information in the world. IBM researchers recently built a nano-abacus in which carbon molecules slide along nanoscopic copper grooves.

Not to be outdone, Cornell University scientists crafted a guitar 10,000 nanometres long, about the size of a single cell, and pluck its six silicon strings - each about 100 atoms wide - with a nanoscopic microscope.

These experiments are not only designed to wow us, but also have practical applications. At these sizes, computers can be woven into clothing, painted onto walls, injected into the bloodstream and travel to diagnose tumours and repair cells in various parts of the body.

Nanotechnology holds tremendous promise, but there are perils too. What potentially harmful effects the new nano-materials, nano-machines or nanobots could have on life and the environment is not known. Nanoparticles could be toxic to the human body, but we don't really know.

Critics of nanotechnology point to chemical pesticides, which were not considered harmful when they began to be widely used in agribusiness in the early half of the 20th century. Only in the 1960s and 1970s were the risks to health and the ecosystem properly understood.

Proponents, though, argue that nanotechnology is likely to provide solutions to the world's most pressing problems - from cleaning our water to maximising energy efficiency to finding cures for diseases - so the potential rewards are greater than the potential risks. We won't know till we are well into the nano-based future.

Tom Yam is a Hong Kong-based management consultant. He holds a doctorate in electrical engineering and an MBA from the Wharton School of the University of Pennsylvania. He has worked at AT&T, Ernst & Young and IBM