Electricity from body movement: 280x more efficient device developed in South Korea
To overcome the limitations of PZT’s inherent rigidity, the researchers engineered a novel three-dimensional architecture for the device.
Researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in South Korea have developed a highly efficient energy harvesting device that converts body movements into electrical energy.
Notably, the new device exhibits an energy conversion efficiency 280 times greater than that of conventional stretchable piezoelectric energy harvesters.
The device utilizes the piezoelectric effect, a phenomenon where certain materials generate an electrical charge in response to mechanical stress. This means that activities like walking, bending, or even subtle movements can be harnessed to produce electricity.
The piezoelectric materials possess an inherent asymmetry in their charge distribution. When subjected to mechanical stress, such as bending or stretching, this asymmetry is further amplified, leading to a separation of charges and the generation of an electrical potential across the material.
This conversion of mechanical energy to electrical energy forms the basis of piezoelectric energy harvesting.
Existing limitations
While the concept of piezoelectric energy harvesting is not new, its application in wearable devices has been hindered by limitations in material properties and device design.
“In the early stages of PENG research, cantilever-shaped inorganic piezoelectric devices were extensively studied, enabling efficient energy harvesting from high-frequency vibration,” said the study led by Professor Jang Kyung-In.
“However, these conventional designs are limited when they are applied to flexible and stretchable formats.”
Many materials with strong piezoelectric responses, such as lead zirconate titanate (PZT), are inherently rigid and brittle.
This makes them unsuitable for integration into flexible and comfortable wearable devices.