For several years, University of Cambridge spin-off Splashpower has hyped a charging "pad" that would juice up an assortment of mobile devices just by setting them on top of a small mat. Recently, Splashpower filed patents that detail the technology and says that the first devices could be released within the year. From New Scientist:
Inside the pad, an array of coils spread a low-power magnetic field low and wide over the pad's flat surface so that devices anywhere on the surface can intercept charging flux (see Graphic). The pad has numerous flat primary coils embedded under the surface. The coils can be of different sizes and shapes: rectangular, circular or ellipsoid.
Splashpower-compatible cellphones, digital cameras or camcorders will have a thin, flat receiver attached to them or inside their casing. The receiver is a sheet of magnetic alloy, the size of a stick of chewing gum, with a coil wound round it. Current induced in the coil when it is on the charging pad is then fed to the device's charging circuit.
