Energy-harvesting rubber sheets could power pacemakers, mobile phones

Power-generating rubber films developed by Princeton University engineers could harness natural body movements such as breathing and walking to power pacemakers, mobile phones and other electronic devices.


The material, composed of ceramic nanoribbons embedded onto silicone rubber sheets, generates electricity when flexed and is highly efficient at converting mechanical energy to electrical energy.


Shoes made of the material may one day harvest the pounding of walking and running to power mobile electrical devices.

Diverse studies have show that, the act to breathe that implies to move the ribs to extract the air out of the lungs and to expel it can generate a watt and the heel that a person gives upon walking it produces up to 70 watts.

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 which power the devices.

The research was funded by the United States Intelligence Community, a cooperative of federal intelligence and national security agencies.

The Princeton team is the first to successfully combine silicone and nanoribbons of lead zirconate titanate (PZT), a ceramic material that is piezoelectric, meaning it generates an electrical voltage when pressure is applied to it. "PZT is 100 times more efficient than quartz, another piezoelectric material," said Michael McAlpine, a professor of mechanical and aerospace engineering, at Princeton, who led the project."