The top technology university in South Korea has developed a plan to power electric cars through recharging strips embedded in roadways that use a technology to transfer energy found in some electric toothbrushes. The plan, still in the experimental stage, calls for placing power strips about 20 centimeters to 90 centimeters wide, or 8 inches to 36 inches, and perhaps several hundred meters long into the top of roads. Vehicles with sensor-driven magnetic devices on their underside can suck up energy as they travel over the strips without coming into direct contact. "If we place these strips on about 10 percent of roadways in a city, we could power electric vehicles," said Cho Dong-ho, the manager of the "online electric vehicle" plan at the Korea Advanced Institute of Science and Technology. The university has built a prototype at its campus in Daejeon about 140 kilometers, or 90 miles, south of Seoul, for electric-powered golf carts, and it is working on designs that would power cars and buses. The system, which can charge several vehicles at once, would allow electric cars and buses to cut down on their battery sizes or extend their ranges. The non contact transfer of electricity works by having magnets and cables on the underside of the vehicle making a connection with the current in the recharging strip to receive power as they travel over it. This inductive charging is employed in some brands of electric toothbrushes, which use a magnetic connection to receive energy while resting in a cradle. The recharging strips, which are attached to small electrical stations, would be laid in places like bus lanes and the roads running up to intersections so that vehicles could power up where traffic slows down, Mr. Cho said. The system will be tested later this year for use in the bus systems of Seoul and other South Korean cities. Some of the country's automakers are also cooperating in the project.