Perpetual motion machines cannot exist, at least according to the Laws of Thermodynamics. Eventually, the energy will leak out and the machine will stop. But if you can provide a machine with an endless external source of energy — such as the sun — it could run forever (or at least until the sun runs down). This is the thinking behind Drayson Technology‘s Freevolt Perpetual Power technology; it grabs tiny amounts of energy out of the air in order to drive sensors, radio transceivers, and other building blocks of the Internet of Things (IoT).

If you understand electrical circuits, the simplified diagram above tells the story. The company has developed a way to extract energy from a radio waves across a range of frequencies. It turns these radio waves into small electrical currents that can trickle charge batteries or provide the energy requirements of low-power devices. It harvests radio waves in the WiFi, cellular data, and digital TV ranges. The result will be devices that can “live” independently, without the need for power cables or changing batteries. Beacons, wearable devices, smart home sensors all could be powered by this technology.

Perpetual Power is already being used for a project called the CleanSpace Tag. This device monitors the carbon monoxide levels of the air around the person carrying the device. This can provide immediate information about your surroundings, but the data will also be aggregated to provide a crowd-sourced composite view of air conditions throughout cities around the world. Energy harvesting technologies like this can help wearable devices “disappear” into our daily lives, and not require the frequent intervention and attention required to keep them recharged.