Researchers at the University of Tokyo have demonstrated a one-milimeter sheet of electronic plastic that can deliver power to devices nearby. The idea is that you could cover, say, a desk with the material and power computers, for example, just by sitting them on top without having to plug them in. The key are organic transistors that are printed right onto the material, MEMS (micro-electromechanical systems) switches that control the flow of power, and copper coils that wireless transmit the current. From News@Nature:
When the sheet itself is plugged in, it can power devices – such as light-emitting diodes (LEDs) strung on a Christmas tree – that are built with a matching receiver coil. When these are placed within 2.5 centimetres of the sheet, the nearest MEMS switch turns on, feeding power to the closest sender coil, which powers the device's receiving coil through induction.The researchers say the transmission of power happens with 81.4% efficiency – compared to 93% efficiency in the wired grid network as a whole – with a "quite low" level of leaked electromagnetic radiation. As a demonstration of the product's safety, the paper shows it powering an LED at the bottom of a bowl containing water and a live fish.
All four layers are produced by literally printing them – the coils using screen printing, the switch and transistor layers with an ink-jet printer (using special electronic inks). So the product is thin, lightweight and mechanically flexible.
