Ultra-Thin, Flexible Film Could Power Next-Generation Wearable Devices Using Body Heat

Image: The ultra-thin, flexible film offers the potential for a sustainable energy source for wearable electronics (Photo courtesy of QUT)

Researchers from Queensland University of Technology (QUT, Brisbane, Australia) have now developed a breakthrough ultra-thin, flexible film that could harness body heat to power next-generation wearable devices, eliminating the need for batteries. This technology could also be applied to cool electronic chips, improving the efficiency of smartphones and computers. This advancement addresses a significant challenge in creating flexible thermoelectric devices that effectively convert body heat into power, offering a potential sustainable energy source for wearable electronics and a more efficient cooling solution for chips.

Most previous research in this field has concentrated on bismuth telluride-based thermoelectrics, known for their high efficiency in converting heat into electricity, making them ideal for low-power applications such as heart rate monitors, temperature sensors, and movement trackers. In a study published in Science, the team introduced an affordable technique for creating flexible thermoelectric films by using tiny crystals, or "nanobinders," which form a consistent layer of bismuth telluride sheets, significantly improving both efficiency and flexibility. The team successfully produced a printable A4-sized film with record-breaking thermoelectric performance, exceptional flexibility, scalability, and low cost, positioning it as one of the top flexible thermoelectrics available.

To achieve this, the team used a "solvothermal synthesis" technique, which forms nanocrystals in a solvent under high temperature and pressure, in combination with "screen-printing" and "sintering" methods. The screen-printing method enables large-scale production of the films, while sintering heats the films to near their melting point, bonding the particles together. The researchers also noted that this approach could be adapted for other systems, such as silver selenide-based thermoelectrics, which might offer a more sustainable and cost-effective alternative to traditional materials.