Small is beautiful: the nano-electric revolution

With manufacturers on a constant mission to miniaturise electrical components, how do you overcome the problem of friction outweighing power as you shrink the size? The solution, says Miklós Kellermayer, Professor of Biophysics at Semmelweis University in Budapest, is not to scale down, but to redesign from the bottom up – with inspiration from the human body..

In 1965, Intel’s co-founder Gordon Moore made an uncannily accurate prediction. He stated that the number of transistors that could be fitted on a square inch of computer circuitry would double every year for the foreseeable future. Forty-five years on, the spirit of Moore’s Law is still with us, with storage capability of a computer chip still doubling every 18 months or so.

Moore’s prediction is all the more remarkable when a basic law of physics hinders the miniaturisation process past a certain point. As you reduce the size of something, the amount of friction increases disproportionally, eventually outweighing the extra power you gain from the weight reduction. Now Professor Kellermayer and his team are researching a new form of power that neatly avoids the problem – using the self-organising, motoric and elastic properties of protein molecules.

“The aim is to develop a computer chip based on individual molecules,” he explains. “We’re exploiting the motor properties of muscle proteins – in an aqueous environment, they are self-organising, and so able to move on their own. The intention is to learn how to apply this movement to create powerful, miniaturised chips, driven by optical switches – much like the way the muscle proteins perform in the human body.”

What Professor Kellermayer is referring to is the startling discovery that certain protein molecules, such as those that modulate the structure of DNA, are able to ‘walk’ along the DNA structure without any external manipulation. Harnessing this mechanical force, and learning to control it through activation and deactivation, could lead to a revolution in the design of novel multi-functional chips and eventually in the electronics industry.

He readily admits such ‘nano-biotechnology’ has seemed wildly futuristic until now. “Fifteen to twenty years ago, the research we are doing now was science fiction – it was only a decade ago that scientists first stretched a protein molecule. But now we have reached the point where we have the potential to try and make this a reality and that’s a very exciting prospect.”

After completing his studies as a medical doctor, Professor Kellermayer moved into the field of bioengineering in muscle proteins, establishing the Nanobiotechnology and Single Molecule Biophysics Group at the University of Pécs medical school in 2000, which he moved recently to Semmelweis University in Budapest. The advanced nanotechnology tools he has developed since then have enabled a level of research only dreamed of until now. “I’m a researcher with a natural curiosity about this subject,” he reflects.

“Learning nature’s secrets and then applying them is the driving force behind what I do. But it’s only been possible with advances in technology. The Atomic Force Microscope for example, not only has the power to scan single molecules but to image them in an aqueous environment and even manipulate them. And the optical tweezers we use apply a laser beam to stretch a molecule, allowing us to observe its elastic properties. In fact we’re now able to observe nanoparticles in vivo, [at NIVIC, the University’s Nanobiotechnology and In Vivo Imaging Center] within a living organism such a mouse, which was unthinkable a few years ago.”

With such drive and technology to hand, Professor Kellermayer can point to some significant progress in the project so far. “The discovery that certain proteins self-organise into highly regular and interconnected structures opened up the possibility of nanoelectricty for us in the first place. The recognition that motor proteins may be artificially linked to such highly organised protein networks paves the way towards manufacturing nanochips with unprecedented functions. Alongside that, we’re gaining a better insight into the elasticity of single molecules - what makes them elastic and how they work. And of course this project is also putting the mechanical forces of biomolecules on the map – something that’s been absent from most biology textbooks until now. It highlights the fact that these biomolecules are actually nanomachines.”

For now, the team is focusing on developing the technology to a workable level, but the commercial application of such devices would be widespread. In the consumer electronics industry it could herald the use of miniaturised chips in computers, smart phones and tv screens for example, while the medical profession could see nanoelectronics used to screen DNA samples or detecting high-resolution images in artificial retinas.

“We’re some way off that yet,” admits Professor Kellermayer “and by that stage, we would be handing over to someone else to develop the device into a viable, mass production commercial application of course. But it is amazing to think that we could be working towards a fully bionic computer or medical device.”

Aside from these longer-term applications, Professor Kellermayer has a more philosophical hope for the future. “As a scientist, I’m fully aware that talk of bionic devices can seem a little scary to the general public! But having enjoyed increased awareness and acceptance in the scientific community, I hope our work can gain a similar profile in the public domain too. We’re not playing God here – we’re merely taking something that exists already, in all living organisms, and applying it to new technology. If we can continue to solve the biophysical mysteries and demonstrate the benefits of that knowledge, then I hope people will be able to understand that biophysical research can be a beautiful thing.”

Click here to access the department of Biophysics and Radiation Biology at Semmelweis University.

Published: Thursday, 20th October 2011