The vibrations of every passing vehicle are now being turned into electricity by a venture company whose technology is powering one of 108 LED (light-emitting diode) lights on the Goshiki Zakura Ohashi bridge over the Arakawa River in Tokyo's downtown Adachi Ward — and whose pioneering work may one day lead to aircraft that fly across oceans and continents without using fossil fuels.

For the time being, though, that LED light shines because it is connected to 10 generators set beneath the roadbed of the Metropolitan Expressway crossing the bridge, where vehicles' vibrations make the pendulums in the generators swing and so generate electricity.

Kouhei Hayamizu, who invented the vibration-power generators and is now president of Soundpower Corp., a Fujisawa, Kanagawa Prefecture-based company, positively lit up himself as he explained: "I am now developing remodeled generators to supply 100 percent of the electricity demanded by the LED lights on the bridge."

The 27-year-old entrepreneur said that generating power from vibrations was one of the ideas he wrote in his notebook when he was at elementary school.

"Electricity enables a loudspeaker to vibrate and make sound, so I wondered whether the process could be reversed to generate electricity from vibrations and sound," he explained.

Ten years later, Hayamizu made that topic the theme of his dissertation when he studied at Keio University's Fujisawa campus in Kanagawa Prefecture. After many failed trials with various materials, he found that substances called piezoelectric elements — made of barium titanium oxides — generate electricity when pressure is applied to them.

Piezoelectric elements are what create sparks in cigarette lighters and gas cookers to ignite flames, he explained. "Actually, many people knew that they could generate power from sound and vibrations. But the amount they generated was very little," said Hayamizu, who explained that his breakthrough was to increase the substance's power-generating efficiency and durability.

In September 2006, during his first year of doctoral studies at Keio, he established Soundpower Corp. to make a business of the new technology he was developing.

As its first venture, the company introduced the "Power-Generating Floor" comprised of 50-cm-square tiles that each produce, through "resonance energy," 0.1 watts of electricity when a person steps on them — enough to illuminate 50 to 100 "Christmas-tree" LED lights wired to the tile.

To date, Soundpower has rented its Power-Generating Floor tiles (at ¥80,000 per six days) to a range of companies across the nation who have used them to promote their events.

"Although lighting can make us more comfortable, some people also say that lights can waste electricity," Hayamizu said. "But by using in-floor technology, people can generate the power by themselves. I believe that floor-power suits today's demand for environmentally friendly products."

The company recently sold its flooring to Kokuyo Office System Co. in Tokyo's central Kasumigaseki district, a company that designs corporate offices and which installed Power-Generating Floors in its renovated office in July 2008 as the energy source for directional lights. The company is now cooperating with Soundpower Corp. in promoting corporate sales of the Power-Generating Floors.

"Power consumption at offices in Japan has been increasing in recent years. We hope the floors will play a role in reducing carbon-dioxide emissions from offices," said Tadashi Shindo, an official at Kokuyo Office System's solution-development section. "Various renewable-energy sources have been developed, but before the invention of Power-Generating Floors there was no source from which people generated electricity themselves."

Soundpower Corp. is currently planning to apply its vibration power to lifestyle products, too. Hayamizu said he is working on producing "Power Shoes," with soles that have built-in vibration-power generators. He explained that a person wearing the shoes would be able to generate electricity simply by walking, and use that to power their portable music player or mobile phone. Delighted, Hayamizu said that an "internationally famous" sportswear maker (whose name he could not reveal) is cooperating with his company in making the shoes.

He also said that he is developing generators that convert sound, through its air vibrations, to power.

"The concept of the vibration and sound-power generators is to utilize all the energy that is discarded in our daily lives," he said.

Actually, he also disclosed that the major European aircraft-builder Airbus, whose products create a massive amount of noise, has contacted him to inquire about developing sound-power generators. So, amazing as it may seem, the dream of aircraft that fly without guzzling gas may be a little closer — and all because of the work of a small and innovative company in Kanagawa Prefecture.

For Hayamizu, though, this is not just about a contract here and a contract there; he is serious about turning vibrations and sound into a major source of electricity in the world of the future.

"I am planning to introduce Power- Generating Floors catering to households by the end of this year. They will be able to be used to generate electricity for lights in corridors and stairs," he said.

So, if you are planning to renovate your house to be environmentally friendly, installing power-generating flooring may be a truly "green" way to go.