The rise of radio, TV, cellular, Wi-Fi and other wireless technology has flooded the world with extra electromagnetic signals, and that trend is only going to continue. Those signals represent a lot of energy to broadcast.
At the same time, while wireless technology lets us carry our gadgets everywhere, slow progress in battery technology means we still need to recharge our gadgets every day, or carry around a heavy brick. When it comes to smaller, low-powered sensors and gadgets, the biggest part is often the battery.
Researchers from the Sensor Systems Lab at the University of Washington have realized that these two problems might actually be one solution. Their answer is to power gadgets using Wi-Fi.
It turns out that a Wi-Fi signal is strong enough to power some types of electronics. In their first attempt, the researchers managed to power a temperature sensor and a battery-less surveillance camera using only Wi-Fi at a dozen feet away.