A breakthrough in energy storage technology could bring a new generation of flexible electronic devices to life, including solar-powered prosthetics for amputees.

In a paper published in the journal Advanced Science, a team of engineers at the University of Glasgow discuss how they have used layers of graphene and polyurethane to create a flexible super-capacitor that can store power from the sun.

They have demonstrated the effectiveness of their new material by powering a series of devices, including a string of 84 power-hungry LEDs and the high-torque motors in a prosthetic hand, allowing it to grasp a series of objects.

The research towards energy-autonomous e-skin and wearables is the latest development from the University of Glasgow’s Bendable Electronics and Sensing Technologies (BEST) research group, led by Ravinder Dahiya (www.gla.ac.uk).

The top layer is made from graphene, a highly flexible and transparent ‘super-material’ formed of carbon layers just one atom thick.

Sunlight that passes through the top layer is captured by a layer of photovoltaic cells below, with any surplus power stored in a newly developed super-capacitor made from a graphite-polyurethane composite.

In laboratory tests, the super-capacitor has been powered, discharged and powered again 15,000 times with no significant loss of function.

Professor Dahiya said: “This is the latest development in a string of successes we’ve had in creating flexible graphene-based devices that can power themselves from sunlight.

"Our new super-capacitor, which is made from inexpensive materials, takes us some distance towards our ultimate goal of creating entirely self-sufficient flexible solar-powered devices that can store the power they generate.

"There’s huge potential for devices such as prosthetics, wearable health monitors, and electric vehicles that incorporate this technology.”