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

2015-2016 E²SHI Seed Grant

Research Team

Rajat Mittal, Professor, Department of Mechanical Engineering. 
Contact Dr. Mittal 
Sung Hoon Kang, Assistant Professor, Department of Mechanical Engineering
Kourosh Shoele, fomer Postdoctoral Fellow and Assistant Research Scientist, Department of Mechanical Engineering
Santiago Orrego, Postdoctoral Fellow, Department of Mechanical 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 system continuously harvests 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 generated by the wind's movement and have the potential to generate sustainable amounts of energy and improve the capabilities of self-powered sensors.

Researchers Mittal and Kang have been 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.


Photo: Postdoctoral Fellow Santiago Orrego developed a piezoelectric flag and has been testing the model on the roof of a building at the Johns Hopkins Homewood campus. Credit: Jay Gould.


Orrego, S.,  Shoele, K., Ruas, A., Doran K., Caggiano, B., Mittal,R., and Sung Hoon Kang. (May 2017.) “Harvesting ambient wind energy with an inverted piezoelectric flag.” Applied Energy, 194: 212-222.


Learn more about the project from Santiago Orrego

What is piezoelectricity? 

I think the environment should be put in the category of our national security. Defense of our resources is just as important as defense abroad. Otherwise what is there to defend?
— Robert Redford, Yosemite National Park dedication, 1985