Future Mouse Pads Could Charge Laptop’s Batteries

Researchers from the University of Tokyo are developing inductive power transfer methods that will allow charging of mobile devices wirelessly. Although similar systems are already close to commercial roll-out, such as UK-based SplashPower, the Japanese technology would seem to promise very thin and flexible charging mats that could be integrated into everyday materials. For example, it could be possible to produce mouse pad that charges battery of laptop and cell phone just by putting mobile device on that pad or near it, the reports say.

However, Japanese researchers say the gadgets would need to be equipped with a coil and special power-harvesting circuitry to use the power pad. As the notebook or the cell phone gets closer to the pad, the electrical resistance of the pad’s coils decreases. The array of transistors detects the exact position of the change in resistance and directs the power flow, which is provided by devices on the second sheet of plastic.

The benefit of sensing the position of the object and selectively feeding power to that area in increased efficiency, explained Dr Takao Someya from University of Tokyo. “Net power-coupling efficiency is 62.3 per cent. Power levels as high as 29.3W have been transferred in this fashion.”

BBC earlier reported, according to the researchers, that the wireless battery charging concepts exploit century-old physics (invented by Nikola Tesla) and “could work over distances of many meters”.

BBC: How Wireless Power Could Work

1) Power from mains to antenna, which is made of copper
2) Antenna resonates at a frequency of 6.4MHz, emitting electromagnetic waves
3) ‘Tails’ of energy from antenna ‘tunnel’ up to 5m (16.4ft)
4) Electricity picked up by laptop’s antenna, which must also be resonating at 6.4MHz. Energy used to re-charge device
5) Energy not transferred to laptop re-absorbed by source antenna. People/other objects not affected as not resonating at 6.4MHz

India Times | Electronics Weekly | BBC | SplashPower