Electricity From a Human Body?
Developed by researchers at the University of California San Diego, the “wearable microgrid” can store energy harvested from the sweat and body movements of a person. This energy can then be used to power low-power-consuming devices, such as an LCD smartwatch or small fitness trackers. The technology utilizes three key components to convert body-sweat and body movements into electrical energy. These include sweat-powered biofuel cells, motion-powered triboelectric generators, and supercapacitors to store the energy. “We’re applying the concept of the microgrid to create wearable systems that are powered sustainably, reliably, and independently,” said Lu Yin, the co-author of the study published in the Nature Communications journal. “Just like a city microgrid integrates a variety of local, renewable power sources like wind and solar, a wearable microgrid integrates devices that locally harvest energy from different parts of the body, like sweat and movement, while containing energy storage”, added the nanoengineering Ph.D. student of Jacobs School of Engineering.
How Does It Work?
Now, to develop the wearable shirt-like product, the researchers screen-printed each of the components onto a shirt. They designed it in such a way so that the components optimize the amount of energy collected. Also, every screen-printed component is washable and flexible. As for how the technology works, once the user wears the microgrid shirt, the triboelectric generators will get to work as soon as the wearer starts moving. Once the subject starts sweating, the biofuel cells absorb the sweat to generate more electric power and store them in the supercapacitors. This way, the microgrid can power devices even when the subject is at rest.
To test the technology, the researchers put the microgrid shirt on a subject for around 30 minutes. During the time, the subject exercised on a cycling machine or ran for 10 minutes and remained at rest for the rest of 20 minutes. The microgrid, during this time, was able to power either an LCD-panel wristwatch or a small electrochromic display that changes colors in response to voltage change.
Future Plans
Now, the researchers say, going into the future, the wearable microgrid could be ideal for athletes or people who exercise a lot. However, as per Yin, they are working on some other designs to integrate the microgrid technology. “We are not limiting ourselves to this design. We can adapt the system by selecting different types of energy harvesters for different scenarios,” Yin said. The study and the development of this project were also supported by the University of California’s San Diego Center for Wearable Sensors and the National Research Foundation of Korea.
