Electricity Transmitted to Auto Tire Through 10cm-thick Concrete
The Toyohashi University of Technology demonstrated its wireless power transmission technology using electric field coupling with automobile tires and the same concrete as used for public roads.
The demonstration took place at WTP Wireless Technology Park 2012, a trade show on wireless technologies, which runs from July 5 to 6, 2012, in Yokohama, Japan.
A research group led by Takashi Ohira, professor at the university's Department of Electrical and Electronic Information Engineering, has been engaged in the research aimed at using wireless power transmission technologies based on electric field coupling (or inductive coupling) for transmitting power to a running vehicle.
The differences from the group's past research results are (1) that electricity as large as 50-60W was transmitted to life-size automobile tires and (2) that there was a 10cm-thick concrete block between the metal plate on the transmission side and the tire. The efficiency of power transmission from the metal plate under the concrete, which is the same as used for public roads in Japan, to the light bulb attached to the tire is 80-90% or higher, Ohira said.
As for the second improvement, the research group said that it will become possible to use the technology with 20cm or thicker concrete, which is sometimes used for actual roads, because of the high conductivity of concrete. To put the technology into practical use, the electric power needs to be increased by 100 times. But the group said that the parts needed for it are relatively cheap and that there is no major problem.