A revolutionary way to power healthcare devices with body heat alone

Researchers at Carnegie Mellon University's Department of Mechanical Engineering have developed a revolutionary way to power healthcare devices using body heat alone.

The promising approach offers a novel solution to battery life concerns for essential medical devices. It involves combining a pulse oximetry sensor with a flexible, stretchable, wearable thermoelectric generator made of liquid metal, semiconductors, and 3D-printed rubber. 

“This is the first step toward battery-free wearable electronics,” said Mason Zadan, the study’s first author. 

Designed to achieve high-precision mechanical and thermoelectric performance with seamless material integration, the system features advances in soft materials and energy management.

“Compared to our previous research, this design improves energy density by about 40 times, or 4,000 percent,” explained Karmel Majidi, professor of mechanical engineering and director of the Soft Machines Laboratory. “The liquid metal epoxy composite (a type of polymer material) enhances the thermal conductivity between the thermoelectric component and the point of contact of the device with the body.”

The research team tested the device on a participant's chest and wrist while at rest and in motion.

“As the participant moves, one side of the device is cooled by increased airflow, while the other side is heated by increased body temperature,” Zadan said. “Walking and running created an ideal temperature difference.”

The researchers are looking to work on improving the electrical performance and exploring how to manufacture the device and transform it from a "prototype" into a product that people can start using.

The study was published in the journal Advanced Functional Materials.