A team of researchers at the University of Cambridge, led by Professor Arokia Nathan are working to develop technologies that would make daily phone charging a thing of the past.

To keep a phone's battery topped up, the team has built a prototype device that recaptures wasted light from and OLED phone screen.

According to researcher Arman Ahnood, only around 36 percent of the light produced by a phone screen is projected forwards – the rest escapes around the edges.

Here comes the science bit

The light-capturing device is made up of an array of solar cells comprising thin-film hydrogenated amorphous silicon that actually sits within the phone's screen.

It is then paired with a thin film supercapacitor to even out the voltage spikes produced by the solar cells to avoid damaging the phone's battery.

Along with extra cells around the edges of the screen, this means that the device can harness ambient light as well as the wasted screen light leaking around the edges.

A 3.7-inch smartphone screen can produce a maximum power output of 5 milliwatts in this way, which would hardly make a dent, but it's a good start.

The prototype devices are still a fair way off production, but we certainly welcome anything that lets our smartphones go even just a little bit longer between charges.

via ieee spectrum