One of the recurring themes here at Health Tech Insider is the question of how we are going to power sensors and other wearable devices for Health Tech applications. Energy harvesting is an attractive solution because it can delay or even eliminate the need to recharge a device.

Researchers at Vanderbilt University have come up with a novel approach to harvesting energy from motion. They have created a thin film using black phosphorus that is 1/5000 as thick as an average human hair, and is capable of producing 40 microwatts per square foot when bent or pressed. Most energy harvesting devices require on relatively high frequency motion, operating at 100 cycles per second (Hertz) of faster. The Vanderbilt material is effective even at 0.01 Hertz: one cycle every 100 seconds. This makes it well suited to extract power from normal human movement.

The power generated by the material could power devices directly, or be stored in batteries or supercaps until needed. This technology could make it practical to have self-powered-sensors that never need to be recharged, or other wearable devices including LCD displays. In addition to generating electricity, the material could also be used as a sensor to detect movement.