Harvesting energy from flow-induced flutter of ‘piezoleaves’ for self-powered sensors

Research Team

Rajat Mittal
Professor, Department of Mechanical Engineering, School of Engineering
Contact Dr. Mittal 
Sung Hoon Kang
Assistant Professor, Department of Mechanical Engineering, School of Engineering
Kourosh Shoele
Post-doc, Department of Mechanical Engineering, School of Engineering

Small-scale electronic sensors and sensor networks are increasingly used for a wide variety of applications, such as ecological monitoring. As the need for environmental monitoring increases in light of climate change, so does the need to improve sensor technology. Most sensors require small, amounts of power but over long durations in order to perform. While the ability of the electronic sensors to sense, process, and transmit information has improved dramatically in recent decades, the same is not true for the sensors’ battery technology and life.

A solution to fill this gap is to use a new type of energy harvesting system, which would help to increase the life and functionality of the sensors. The novel system would continuously harvest energy from the environment by using piezoelectric materials. Piezoelectricity is generated from the movement of piezomembranes similar to the flutter of leaves in the wind. These energy-harvesting devices, or “piezoleaves,” are moved by wind and have the potential to generate sustainable amounts of energy and improve the capabilities of self-powered sensors.

Researchers Mittal, Kang, and Shoele are using computational modeling, advanced manufacturing, and experimental testing to research on the performance and to optimize the piezoleaves. The research team, which also includes graduate and undergraduate students, are constructing their own customized piezoleaves and testing them in wind-tunnels. Ultimately, the researchers hope to use such piezoleaves to form “trees” to harvest both solar and wind energy through thousands of piezoleaves containing solar cells. By generating a comprehensive set of preliminary data on piezoleaves, the team will help electronic sensors become self-powered and contribute scientific knowledge in a field that is currently uncharted.


What is piezoelectricity? 

The research team installed a piezoelectric flag on top of Garland Hall at the Johns Hopkins
Homewood campus to demonstrate how ambient wind can be harvested to generate energy.
See the video showing a live performance of the flag

When we were young, we had trouble seeing the cattle in the grassland. Now we can see the mice.
— Chinese farmers as quoted in The Coming Famine by Julian Cribb