No. 380: Wireless data transmission and power supply to a memory card (December 14, 2011)

Two professors of Keio University developed a technology to transmit data and supply power to a memory card wirelessly. Wireless data transmission and power supply will eliminate metal terminals from a memory card. In addition, metal terminals will be free from deterioration, and a circuit to prevent fracture due to static electricity will not be necessary. Accordingly, it will be possible to make a memory card less glitchy and totally waterproof.

Because the research team already succeeded in wireless data transmission, it tried to unwire power supply. A memory card gets electricity from a device like digital camera and uses it to write and read data. During this short period of several tens of microseconds, power consumption fluctuates more than 10 times. The research team applied the magnetic coupling technology that transmits signals by creating a magnetic field with a coil, and successfully increased and decreased electric energy instantaneously and supplied electricity of one watt necessary to run a memory card with an efficiency of 50%. The coil can be made easily because all that is necessary is to wire it on the substrate. The research team is planning to make the new technology applicable to the international standards in alliance with memory card manufacturers.