Researchers implement a method to harvest electricity from human motion


Clothes that double up as a cell-phone charger could be a reality soon as researchers have found a way to generate electricity from human motion.

energy harvesting

Researchers from Nanomaterials and Energy Devices Laboratory of US-based Vanderbilt University have developed an ultra-thin energy harvesting system that can generate small amounts of electricity when the system is bent or pressed even at extremely low frequencies like that of human motion.

“In the future, I expect that we will all become charging depots for our personal devices by pulling energy directly from our motions and the environment,” said, Cary Pint, Assistant Professor of Mechanical Engineering, Vanderbilt University.

The basic building blocks of the harvester are about 1/5,000th the thickness of a human hair. The technology could incorporate in devices as thin as needed for specific applications.

human motion

The device is made from layers of black phosphorus that are only a few atoms thick. Bending their prototype device produces as much as 40 microwatts per square foot. Also, sustain current generation over the full duration of movements as slow as 0.01 Hertz, one cycle every 100 seconds.

The researchers acknowledge that one of the challenges they face is the relatively low voltage that their device produces. It’s in the millivolt range. However, researchers applying fundamental insights of the process to step up the voltage.

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One of the futuristic applications of this technology might be electrified clothing. It could power clothes impregnated with liquid crystal displays. The display allows wearers to change colors and patterns with a swipe on their smartphone.

Pint also believes there are potential applications for their device beyond power systems. When incorporated into clothing, the device can translate human motion into an electrical signal with high sensitivity that provides a historical record of movements.

More information: [ACS Energy Letters]