Paper antennas pull electricity from the air
The air is full of energy — not in a woo-woo crystal-gazing way, but in a scientific electromagnetic-radiation-from-TV-stations-and-phone-networks kind of way. That ambient energy is just being wasted. But a team from Georgia Tech is developing inkjet-printed paper antennas that could generate enough energy to power a small gadget, right out of thin air.
The researchers have already successfully operated a temperature sensor using electromagnetic energy captured from a television station that was half a kilometer away. They are now preparing another demonstration in which a microprocessor-based microcontroller would be activated simply by holding it in the air.
Right now it's all sensor this and microcontroller that, but when combined with a battery, the energy-scavenging antennas could be used to power larger devices.