Researchers have presented the concept of wireless energy transfer from the road through the steel belts in the tires to the electric car.
This study has been done by researchers at Toyohashi University of Technology (Japan) and has been published online in the IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission.
Researchers have showed that the energy can be transmitted to the steel belts inside the tires by using electrodes or metal plates hidden in the road. They used the displacement current at high frequency to move from the underground through the insulated rubber tread to the steel belt. That energy transferred through the dielectric coupling was utilized to propel 1/32 scale of an electric vehicle as reported by Green Car Congress. The car moved with the efficiency of more than 75% at 52 MHz.
It is the first demonstration of electric power transfer via the tires to the car.
According to the researchers, the energy transfer is equivalent to the charging and discharging a lithium ion battery.
Suzuki, Y. ; Sugiura, T. ; Sakai, N. ; Hanazawa, M. ; Ohira, T. (2012). Dielectric coupling from electrified roadway to steel-belt tires characterized for miniature model car running demonstration EEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission