LONDON, Feb. 14 (Xinhua) -- Scientists in the United States have developed novel brush-like fibers that generate electrical energy from movement, according to the latest issue of Nature published on Thursday.

The fibers made by scientists at the Georgia Institute of Technology in Atlanta can be woven into a material that could be used for self-powering clothes, shoes or biological implants such as pacemakers which harness body movement to power portable electronic gadgets.

The materials could also be used in tents or other structures to harness wind energy, the scientists said.

The scientists under the leadership of Zhong Lin Wang took standard synthetic Kevlar fibers and coated them with tetraethoxysilane, onto which they stuck a layer of zinc oxide. Crystals of zinc oxide grow outwards, forming crystalline rods protruding from the fibers like the hairs on a brush.

The power that comes from the zinc oxide is piezoelectric, but when mechanical stress such as bending, crushing or stretching is applied to a piezoelectric material, it produces a voltage.

The basic power-generating system developed by the team involves two of these fibers intertwined. One of the two has its "brushes" coated with a thin layer of gold. When the fibers rub against each other, the stiffer gold-coated brushes bend the non-coated brushes. Because of the piezoelectric effect, a charge builds up on these bristles, and is gathered up by the gold-coatedones.

Wires attached to the ends of the gold-coated and non-gold-coated fibers can carry the current to a device, such as a light bulb.

The brushes can be made easily in a laboratory, in beakers, at 80 degrees centigrade, Wany said, explaining that when two strands are pulled and pushed against each other at a frequency of 80 times a minute, 5-picoamp pulses of electricity are produced.

Although this is a tiny amount, when a number of the fibers were woven into a yarn, the effect was much greater, Wang said, adding that a yarn made from six fibers produced a current up to 50 times greater than that measured for the two-fibre nanogenerator.

The biggest system made so far by the scientists has comprised only six fibers. Scientists estimate that a square meter of material could produce between 20 and 80 milliwatts of power from normal mechanical vibrations such as footsteps.

The research team is working to optimize the system. Wang said that he has patents for the fibers and a number of companies are interested in developing the technology.

Scientists expect a material to be produced within three years that is fully functional, flexible and wearable, although whether it will be fashionable remains to be seen.

As for applications, Wang imagines a "power shirt" being made. With this, he suggests applications for soldiers to power radio equipment, for example.