Powering up: Seeking new ways to harvest energy for wearable devices

Ifana Mahbub and her lab

Ifana Mahbub, assistant professor of electrical engineering, is developing a new, self-powered wearable sensor that could be used to track motion activities like walking, running, or biking and transmit the data wirelessly.

Backed by a $367,994 grant from the National Science Foundation, the team’s goal is to eliminate the need for batteries and chargers found with other common wearable devices such as the Fitbit or Apple Watch. 

“The novelty of this project is that we’re going to use the electrical energy generated when liquids repeatedly come into contact with a charged electrode. This phenomenon, termed reverse electrowetting, produces a very small amount of electrical energy but when the electrode is very porous, we believe that we will be able to produce 50 times more energy than competing energy harvesting mechanisms,” said Mahbub, the principle investigator on the project. “Also, the efficiency of current energy harvesting approaches is rather poor at lower frequencies, and we want to see if our method will allow us to create smaller and energy-efficient devices that can yield higher power.”

“We also want to be able to identify the type of motion the person wearing the device is experiencing – be it walking, running, or biking – through the frequency of their movement,” said Russell Reid, co-principle investigator and assistant professor of mechanical engineering at Dixie State University. “A miniaturized integrated circuit chip will also be developed that will make the energy harvester highly suitable for other industrial and biomedical applications.”

The project also includes an educational component for K-12 students interested in science, technology, engineering and math.

“This summer, the departments of Electrical Engineering and Mechanical and Energy Engineering at UNT are partnering up to provide an energy harvesting activity for students who enroll in our summer camp,” said Mahbub. “Eventually, we’re going to expand the summer camp to include a wearable device track that students could choose to specialize in.” A similar outreach program also will be implemented at Dixie State University.

Some UNT engineering undergraduate students also will have the opportunity to learn more about the new and evolving field through senior design.

“We’re also planning to have a joint-senior design project between Electrical Engineering and Mechanical and Energy Engineering where undergraduate students will team up and work together on self-powered systems,” she said.