UK entrepreneur showcases device to wirelessly power small devices

Mobile users may be able to ditch their chargers in the future with the development of a device that produces electricity using 'thin air'.

The technology developed by engineers turns radio frequency (RF) energy into power for wearables and gadgets around users' homes.

The technology called Freevolt transforms energy in the signals created by TV, Wi-Fi and mobile networks into a current that could be  'harvested' by compatible devices.

The concept behind the technology was not new and similar systems had been created at the University of Washington.

Its inventor is Paul Rudd Drayson, who is a British businessman, amateur racing driver and former minister of science in the UK's Department for Business, Innovation and Skills.

According to Drayson, who has been knighted Lord Drayson, "Companies have been researching how to harvest energy from Wi-Fi, cellular and broadcast networks for many years."

"But it is difficult, because there is only a small amount of energy to harvest and achieving the right level of rectifying efficiency has been the issue - up until now.

"With Freevolt, we have created something special. For the first time, we have solved the problem of harvesting usable energy from a small RF signal."

In simple terms the Freevolt antenna receives the RF signal and feeds it to a rectifying circuit, which turns the signal into direct current (DC).

The DC energy was then fed into a power management module that boosted the voltage and it was this voltage that was used to charge a battery or other energy source, such as a super-capacitor for instance.

The technology enabled low-energy devices to operate without the need to be plugged in.

The technology was designed to power the smart devices that made up the the 'internet of things'.

The new system was showcased by the entrepreneur at the Faraday Theatre at London's Royal Institution, where Michael Faraday once worked on electromagnetism.

Lord Drayson told the BBC, ''It doesn't require any extra infrastructure, it doesn't require us to transmit any extra energy, it's recycling the energy which isn't being used at the moment''.

In addition to scavenging energy from mobile phone networks, Freevolt also takes power from wireless internet and digital TV broadcasts.

The technology that Freevolt is based on had been around for some time but had not been used in any commercial products until now.

In 2013 Drayson Technologies had set a world land speed record for a lightweight electric car, reaching a speed of 204.3 mph.