Cheap wearable device converts body heat into electricity

Researchers from CU Boulder have developed a new low-cost wearable that can turn the human body into a battery. The wearable devices stretch enough that they could be worn like a ring, bracelet, or any other accessory that touches the skin. The device leverages the person's body heat by employing a thermoelectric generator converting the body's internal temperature into electricity.

One of the researchers said the team wants to power wearable electronics without requiring a battery. Researchers on the project have been able to generate about one-volt electricity for every square centimeter of skin, which is less voltage per area than most existing batteries produce. While voltage produced is relatively small, the team says it's enough to power electronics like watches or fitness devices.

Other wearable thermoelectric devices have been created in the past. The new device created by the researchers can heal itself when damaged and is fully recyclable. The design makes the entire system stretchable without introducing strain to the thermoelectric material, which is traditionally very brittle. As the body heats up and radiates heat to the environment, the new wearable would capture that flow of energy without letting it go to waste.

Adding more power generating capacity to the wearable device is accomplished by adding in more blocks of generators. That means smaller units can be combined into a larger unit similar to building something from Lego bricks. The wearable devices are also resilient, and if the device tears, it could be pinched back together where it would seal up in a few minutes.

When the device reaches the end of its lifetime, it can be dipped in a solution that will separate the electronic components and dissolve the polyimine bases allowing the ingredients to be reused. The goal is to make the devices cheap and to have zero impact on the environment.