Atom-sized machines attract serious cash

Since the publication of Dr Eric Drexler's book Engines of Creation in 1982, molecular nano-technology has been a controversial subject. Dr Drexler both defined the field and made it controversial by painting a futuristic vision and not explaining how his vision could be achieved. Nano-technology is a weird branch of science that involves the creation of machines and materials 10,000 times smaller than the full stop at the end of this sentence.

For decades, sceptics have scoffed at the notion that one day science may be capable of building tiny nano-robots that could, for instance, be injected into the bloodstream to eat cancers, tune heart valves and gather toxins. However, at this year's Foresight Institute conference in Silicon Valley, scientists demonstrated that some of the basic building blocks - the grammar if you will - are already being defined.

Large organisations such as NASA, Sun and IBM have begun to fund research in the field and there's even a new breed of startup dedicated to building nano-scale devices. "Even if aspects of nano-technology are pipe dreams today, there will be by-products that have applications on their own," said Dr Deepak Srivastava, head of nano-technology at NASA.

"These are things that we will be able to do in three or four years such as create new super strong materials, tiny nano sensors that can detect atmospheric pollution and a new generation of microprocessors." At the conference, Cornell scientist Dr Carlo Montemagno demonstrated that nano-scale robots may not be too far away after all. Dr Montemagno and his team created the world's first nano-scale motor by modifying E. coli bacteria. In living cells, energy is produced by the FI protein by taking adenosine diphosphate (ADP) driving through a cell generator and transforming into adenosine triphosphate (ATP).

"The protein has a barrel structure and in the centre is a helix coil that sticks straight up," said Dr Montemagno. "As the ADP travels though the barrel, the coil spins creating ATP. What we do, is reverse the process."

In short, they turn the cell generator into a motor by reversing the motion. With this motor, Dr Montemagno hopes to create a pharmacy in a cell that will enable the creation of targeted drug-delivery robots. Meanwhile, other papers presented at the conference included developments - in nano lithography - a technology to etch designs or patterns onto single atoms.

What is the use of this you may ask? Well, currently micro-processor technology relies on sophisticated methods to etch channels onto the surface of a silicon chip. These channels provide the pipes on which data travels. "In about 10 years, Moor's law will run out of gas," said Dr Srivastava. "Then we will need an alternative to silicon-based technology. I believe nano technology may provide that alternative."

Meanwhile, conference sponsor, Zyvex, is attempting to do what the sceptics say is impossible - build a nano-technology assembler or a device that can build materials or machines one atom at a time. The company is using atomic force microscope tips to pick up and manipulate single atoms.

Last year, the company made the headlines by discovering a way to place atoms next to each other. However, at the moment there is no way to bond the atoms together.

"One very large missing piece of the puzzle is the mechano chemistry," said Mr Jim Von Ehr, Zyvex CEO and founder. If Zyvex can build an assembler, the machine's first task will be to build a better version of itself as human-built assemblers are too big to create truly nano-scale devices.

Meanwhile, NASA is working on creating super strong materials using carbon nano tubes. These are sheets of hexagonal carbon atoms wrapped into cylinders. They have a diameter of approximately 1/10,000 of a human hair, are capable of carrying a very high current and are one sixth of the weight and 100 times stronger than steel.

NASA hopes to reinforce polymer-based plastics with carbon nano tubes (in a similar way as concrete is reinforced with steel) to build very strong light weigh prosthetic limbs or false teeth. The technology, originally developed for use on space crafts, can also be used to build better materials such as surgical tools.

Niall McKay is at niall@niall.org