Ossia has some neat long-distance, wireless power transmission technology that's ideal for delivering power to mobile and IoT devices. At the Consumer Electronics Show, they were demoing a wirelessly powered table that could in turn charge short-range, wireless charging devices like smartphones. While the latter typically must essentially be in close contact with the charging unit, Ossia's system works within rooms.
There are a number of wireless power transmission techniques. Ossia's patented methodology transmits power to a device using a number of paths rather than one high-power, focused transmission. How it determines this multipath transmission is interesting as well. It does so by sending signals from the source; the transmitter receives some of these signals and sends back power based only on the signals it receives (see figure).