http://techcrunch.com/2013/09/09/cota-by-ossia-wireless-power/ I am impressed. If they can deploy this device city wide, then we don't need any more chargers. It also means future wearable devices can be designed in much powerful chips without worrying about battery life. This is the most inspiring demo I have seen so far in this disrupt.
Quote: “What we’re doing uses the same frequencies as Wi-Fi ...”<p>So they're charging batteries from a 30 foot distance using an RF field at multiple gigahertz? What's to prevent interference with other devices in the same frequency band? Let's say the emitter emits one watt of RF -- it's probably higher, but just for the sake of argument. A typical Wi-Fi access point uses 50 milliwatts, or 1/20th the power of the charging transmitter. This means existing spectrum users would be overwhelmed by wide adoption of these devices.<p>Also, there are legitimate health concerns about being near a cell phone emitting 100 milliwatts of RF power. How can a device that emits ten times that power level, or more, be assumed to be safe near people?<p>> If they can deploy this device city wide, then we don't need any more chargers.<p>Yes, but we won't have any more wireless access points -- they'll be overwhelmed by higher-powered competitors.