A device that can harvest energy from the human knee during walking has been developed by researchers from the Chinese University of Hong Kong. Interestingly, the device does not demand a whole lot of effort from its wearer. The device generates up to 1.6 mW of power without significant change in breathing patterns or oxygen consumption by the wearer according to the work demonstrated by the researchers’ team. It can be expected that wearable electronics, body-worn sensors, and prostheses can all be powered by the help of this device one day.
A variety of devices had been developed with the previous work of energy harvester, out of which some could generate a few watts, however, they were heavy. In the case of some other devices, powering them required increased efforts by the wearer of the device. The newly developed smart-material-based energy harvester (SM-EH) by the hong Kong researchers, address these concerns.
For the device to work, the wearer needs to strap the generator at the shin and thigh, thus positioning the components close to the knee. a thin piezoelectric material is bent as the user takes a step; which consequently generates power. Continuous power is generated while the user is in motion as the device is bent and unbent while the user is walking.
Power generation as a result of different walking speeds, measurement of oxygen and CO2 production by the user with and without the device were tested by the researchers. The result was that the new generator did not require additional effort by the wearer to produce electric power. Additionally, the weight of the device is merely a pound or less and it can successfully generate enough power for GPS devices and health monitoring equipment.
According to the senior author of the study, Wei- Hsin Liao, self-powered equipment can enable users to get rid of the inconvenient daily charge. He also said that this energy harvester would further the development of self-powered wearable devices.
Nancy Lojas has a Pharmaceutical background. She is pursuing a Masters Degree from the University of Toronto and loves to write about research, discoveries & trends in the Healthcare sector.