A computer touch screen that powers itself? It may only be five years until your iPad has this. Technology Review reports that Samsung and Sungkyunkwan University (Korea) have teamed up to develop an energy-scavenging touchscreen piezoelectric system that uses nanorods sandwiched between pieces of plastic film  coated with a graphene electrode layer to create a flexible, transparent surface that may power the gadget it is attached to.

Small initial prototypes produced 20 nanowatts per square centimeter using finger pressure, but the group says larger, more recent prototypes (about 200 centimeters square) devices are now producing a microwatt per square centimeter. They say practical device that utilize the system may be available in five years and that roll-to-roll film production techniques can be used. A report on some of this work has been published in Advanced Materials.

This ability might provide ammunition for some form-factor changes in devices. Roll-up screens, for example have been discussed for some time, but the act of rolling and unrolling a screen could give an extra boost of power.