Only 15 years after University of California, Berkeley, engineers built the first micro-scale motor, a UC Berkeley physicist has created the first nano-scale motor - a gold rotor on a nanotube shaft that could ride on the back of a virus.

"It's the smallest synthetic motor that's ever been made," said Alex Zettl, professor of physics at UC Berkeley and faculty scientist at Lawrence Berkeley National Laboratory. "Nature is still a little bit ahead of us - there are biological motors that are equal or slightly smaller in size - but we are catching up."

Zettl and his UC Berkeley graduate students and post-docs report their feat in the July 24 issue of Nature.

The electrostatic motors represent a milestone in nanotechnology, and prove that nanotubes and other nanostructures several hundred times smaller than the diameter of a human hair can be manipulated and assembled into true devices.

Zettl and other scientists had previously made transistors from nanotubes, but this device is different, he said.

Such motors could have numerous uses, Zettl said. Because the rotor can be positioned at any angle, the motor could be used in optical circuits to redirect light, a process called optical switching. The rotor could be rapidly flipped back and forth to create a microwave oscillator, or the spinning rotor could be used to mix liquids in microfluidic devices.

The motor is about 500 nanometers across, 300 times smaller than the diameter of a human hair. While the part that rotates, the rotor, is between 100 and 300 nanometers long, the carbon nanotube shaft to which it is attached is only a few atoms across, perhaps 5-10 nanometers thick.

In 1988, UC Berkeley electrical engineering professor Richard Muller and colleagues in the Berkeley Sensor & Actuator Center (BSAC) fabricated from silicon the world's first operating micromotor. Their electrostatic motor was 100 microns across, or about the width of a human hair.

While the microelectromechanical system (MEMS) motor still awaits appreciable industrial application, Muller said, other actuated MEMS devices have become commonplace. MEMS accelerometers, in part based on micromachining technology developed in BSAC, are now used in almost all automobile airbag deployment systems and in many heart pacemakers. MEMS micromirror arrays are vying with liquid-crystal arrays in state-of-the-art display projectors.

One unexpected difficulty is that the techniques for measuring the motor's speed are as yet too crude. The team's scanning electron microscope (SEM) can take pictures every 33 milliseconds and no faster, so they can't tell whether the rotor spins or flips faster than 30 times per second.

Microwave frequencies, common in communication networks, are above a billion cycles per second, in the gigahertz frequency range.

The motor's shaft is a multiwalled nanotube, that is, it consists of nested nanotubes much like the layers of a leek. Annealed both to the rotor and fixed anchors, the rigid nanotube allows the rotor to move only about 20 degrees. However, the team was able to break the outer wall of the nested nanotubes to allow the outer tube and attached rotor to freely spin around the inner tubes as a nearly frictionless bearing.

To build the motor, Zettl and his team made a slew of multiwalled nanotubes in an electric arc and deposited them on the flat silicon oxide surface of a silicon wafer. They then identified the best from the pile with an atomic force microscope, a device capable of picking up single atoms.

A gold rotor, nanotube anchors and opposing stators were then simultaneously patterned around the chosen nanotubes using electron beam lithography. A third stator was already buried under the silicon oxide surface. The rotor was annealed to the nanotubes and then the surface selectively etched to provide sufficient clearance for the rotor.

When the stators were charged with up to 50 volts of direct current, the gold rotor deflected up to 20 degrees, which was visible in the SEM. With alternating voltage, the rotor rocked back and forth, acting as a torsional oscillator. Such an oscillator, probably capable of microwave frequency oscillations from hundreds of megahertz to gigahertz, could be useful in many types of devices - in particular, communications devices such as cell phones or computers.

With a strong electrical jolt to the stators, the team was able to jerk the rotor and break the outer wall of the nested nanotubes, allowing the rotor to spin freely on the nested nanotube bearings. Zettl had made similar bearings several years ago, but this was the first time he had put them to use.

Interestingly, the rotor does not continue spinning for long once the electricity is turned off. It is so small that it has little inertia, so any tiny electric charges remaining on the device after it's turned off tend to stop the rotor immediately.

Zettl expects to be able to reduce the size even further, perhaps by a factor of five. For the moment, though, he and his team are trying to make basic quantum measurements, such as the conductance through the nanotubes and the amount of friction in the bearings.

Zettl's collaborators on the paper are graduate students A. M. Fennimore, T. D. Yuzvinsky and John Cumings and post-docs Wei-Qiang Han and M. S Fuhrer. Fuhrer now is with the Department of Physics at the University of Maryland, College Park. Cumings is now with the Department of Physics at Stanford University.

The work is supported by the National Science Foundation and the Office of Energy Research of the U.S. Department of Energy.

Cancer Research UK scientists have found the location of an important new gene which pre-disposes people to skin cancer, according to a study published Friday in the American Journal of Human Genetics.

The researchers are part of the international team close to isolating the gene, which they have found to sit on a tiny part of chromosome 1 - one of the bundles of DNA containing our genes.

Inheriting a faulty version of the gene is thought to give people a much higher than average chance of developing malignant melanoma - the most dangerous form of skin cancer - and may be responsible for up to a third of inherited cases.

Scientists believe the study provides a valuable insight into the way in which melanoma develops, and in the future, will allow doctors to identify, monitor and advise those more susceptible to the disease to help them reduce their risk.

The most important cause of melanoma is exposure to the sun, but scientists think that, in around 10 per cent of cases, inherited genes play a role.

Past research has already identified two genes - CDKN2A and CDK4 - which increase a person's risk of melanoma when inherited in a faulty form. But scientists know other genes are likely to exist because CDKN2A and CDK4 only account for around 30 per cent of inherited cases.

The team searched for new risk genes by analyzing genetic data from around 80 Australian, European and American families, with three or more cases of melanoma, that weren't caused by a faulty version of either the CDKN2A or CDK4 genes.

They found that a number of the families had the particular stretch of DNA on chromosome 1 in common and had inherited it in a pattern that matched the inheritance of melanoma.

The team looked specifically at families where individuals had developed melanoma at an early age - a sign that the disease is inherited rather than being caused by damage to genes during a person's lifetime. They found those families with the earliest age of onset were most likely to carry this particular region on chromosome 1.

Researchers say the more immediate implications of the study will be to open up new lines of work that look at how damage to the gene affects the cell, leading to cancer. Understanding how this happens will help in the search for new treatments for the disease.

Jolting tumors with a low dose of electricity may make them more susceptible to chemotherapy, Israeli researchers said on Friday.

They said they had cured up to 80 percent of laboratory mice of cancer using their low-voltage field, depending on the type of cancer. They hope to begin human tests later this year.

Cancer researchers are quick to warn that it is often much easier to "cure" a laboratory mouse of cancer than it is to treat people.

Lab rodents used in cancer research are specially bred to be susceptible to cancer and are artificially infected with tumors, while human cancers develop slowly and for various reasons.

But Yona Keisari of Tel Aviv University believes his team's findings, published in the journal Clinical Cancer Research, are especially significant as they waited until there were established metastases in the lungs and liver of the animals before treatment.

A metastasis is a cancerous cell that had spread from the initial tumor to somewhere else in the body.

He said the electrical charge stimulates the body's immune response.

Keisari's team tested mice with a variety of tumors that had spread, including breast, colon, prostate and melanoma.

They gave the mice standard chemotherapy agents such as cisplatin, taxol or 5-fluorouracil, then applied a low voltage current.

He said his team was seeking approval for clinical trials in human cancer patients in October or November.

Melbourne biotech company Starpharma has achieved a milestone by gaining clearance to proceed with human clinical trials of a new dendrimer nano-drug under US Food and Drug Administration (FDA) regulations.

The project - SPL7013 Gel (VivaGel) - will be used as a preventative against the transmission of HIV during sexual intercourse. VivaGel has been highly successful in preventing infection in monkey trials using a humanized strain of simian immunodeficiency virus (SHIV) and will now progress to human safety trails in Australia.

Dendrimers are one of the main building blocks of the science of nanotechnology and Starpharma has patents in using dendrimers as pharmaceutical products.

The Victorian company, Institute of Drug Technology Australia Limited (IDT) has assisted in Starpharma over a number of years in developing VivaGel microbicide and it is planned that IDT will provide further assistance with the initial Phase I human trials in Australia.

Boeing officials filed court documents Thursday in the U.S. District Court in Orlando, Fla., to dismiss nine counts in a civil suit brought against the company by Lockheed Martin.

Calling the suit an "effort to damage Boeing's reputation through…opportunistic litigation," the filing moves to dismiss all racketeering and antitrust allegations. According to George Muellner, Air Force Systems senior vice president and general manger for Boeing, "Lockheed Martin is trying to stretch alleged facts into violations of laws that do not fit this case.

Lockheed Martin Corp. filed suit on June 10, 2003 against competitor Boeing Co. and three of its former employees, claiming Boeing used Lockheed internal documents to win an Air Force rocket contract.

The 23-count complaint, filed in U.S. District Court in Orlando, Fla., claims a former Lockheed employee gave Boeing more than 37,000 pages of documents that include financial details on Lockheed's planned bid for the $1.88 billion contract.

The contract, part of the Air Force's Evolved Expendable Launch Vehicle Program, was divided between the two companies in 1999. But Boeing was eventually awarded 21 rocket launches, while Bethesda, Md.-based Lockheed was given seven.

Lockheed's lawsuit came a day after Chicago-based Boeing ran a full-page advertisement in several national newspapers acknowledging that some of its employees improperly used the proprietary documents to win the contract.

Lockheed and Boeing collaborate on several major contracts, including the F-22 jet, the proposed national missile defense system and United Space Alliance, a joint venture that operates much of the space shuttle program.