Four U.S. students have developed shoes that extract energy with ever step to power portable electronics and, perhaps someday, life-preserving medical devices, U.S. media reported Wednesday.

Four mechanical engineering students at Rice University in Houston, for a project required for graduation, created PediPower shoes, which deliver 400 milliwatts of energy through wires that connect the shoes to a belt-mounted battery pack, according to on- line version of Texas Medical Center News.

The students, Carlos Armada, Julian Castro, David Morilla and Tyler Wiest, focused their attention where the rubber meets the road to create a shoe-mounted energy generation. They knew of a previously patented device that draws energy from the motion of the knee, and decided to apply those principles to the foot, according to the report.

Working with the Motion Analysis Laboratory at Shriners Hospital for Children in the Texas Medical Center, the students discovered that the force at the heel delivered far more potential for power than any other part of the foot, so they selected the heel-portion of the shoe to generate power.

When the PediPower shoe hits the ground, a lever arm strikes first. The arm is attached to a gearbox that replaces much of the shoe's sole and turns the gears with each step. The gears drive a motor mounted on the outside of the shoe that generates electricity to send up to the battery.

Right now the shoe is simply a prototype, and is too large for day-to-day wear. The students expect the project to be picked up by another team at Rice in the fall, with the hope they can refine the materials, shrink the size and boost the power output, all of which will get PediPower closer to being a commercial product, according to the report.

(Source: Xinhua)