Researchers at Colorado University (CU) Boulder have developed a new, low-cost wearable device that transforms the human body into a biological battery. The device is stretchy enough that it can be worn like a ring, a bracelet or any accessory that touches the skin. The device taps into a person’s natural heat, employing thermoelectric generators to convert the body’s internal temperature into electricity.
“In the future, we want to be able to power your wearable electronics without having to include a battery,” said Jianliang Xiao, senior author of the paper and an associate professor in the Paul M. Rady Dept. of Mechanical Engineering.
The device can generate about 1 volt of energy for every square centimeter of skin space. This is less voltage per area than most existing batteries can provide, but it is enough to power small wearable electronics, such as a watch or fitness tracker. What makes this device different from previously developed thermoelectric wearable devices, is that it’s stretchy, can heal itself when damaged and is fully recyclable.
Power can be boosted by adding in more blocks of generators, similar to building with Lego toys. The researchers have calculated that a person taking a brisk walk could use a device the size of a typical sports wristband to generate about 5 volts of electricity, which is more than the power in many watch batteries.
The new devices are also as resilient as biological tissue. If your device tears, for example, you can pinch together the broken ends, and they’ll seal back up in just a few minutes. And when you’re done with the device, you can dunk it into a special solution that will separate out the electronic components and dissolve the polyimine base, so that each of the ingredients can be reused.
Coauthors on the new paper include researchers from China’s Harbin Institute of Technology, Southeast University, Zhejiang University, Tongji University and Huazhong University of Science and Technology.