U.S. scientists say they have developed power-generating rubber film that can harness body movements to power devices such as pacemakers and cellphones.

Princeton University engineers said their new material is composed of ceramic nanoribbons embedded onto silicone rubber sheets. They said the material generates electricity when flexed and is highly efficient at converting mechanical energy into electrical energy.

The scientists envision shoes made of the material using walking and running to power mobile electrical devices. And, they added, placed against the lungs, sheets of the material could use breathing motions to power pacemakers, obviating the current need for surgical replacement of the batteries that power the devices.

A paper detailing the study, which included postdoctoral researcher Yi Qi and Professor Michael McAlpine, appears in the early online edition of the journal Nano Letters.