Revolutionary Film Powers Wearable Devices Using Body Heat, Could Replace Batteries

Researchers led by QUT have developed an ultra-thin, flexible film that uses body heat to power wearable devices, offering a sustainable alternative to batteries. This innovation also has potential applications in cooling electronic chips.

A new breakthrough may soon change the way we power our wearable devices. Researchers led by Queensland University of Technology (QUT) have created an ultra-thin, flexible film that harnesses body heat to generate electricity, potentially replacing batteries for many devices.

This innovative technology, published in the journal Science, enables the film to be used not only in wearables but also in cooling electronic chips in smartphones and computers.

Zhi-Gang Chen, a professor in the School of Chemistry and Physics at QUT who led the research, emphasized the significance of this development.

“Flexible thermoelectric devices can be worn comfortably on the skin where they effectively turn the temperature difference between the human body and surrounding air into electricity,” Chen said in a news release. “They could also be applied in a tight space, such as inside a computer or mobile phone, to help cool chips and improve performance.”

The team, composed of experts from various disciplines, including chemistry, physics and materials science, tackled the longstanding issues of flexibility and efficiency in thermoelectric devices.

Prior research largely focused on bismuth telluride-based thermoelectrics, known for their high efficiency in converting heat into electricity, making them suitable for low-power applications such as health monitors.

In their groundbreaking study, the team introduced a new, cost-effective method to create flexible thermoelectric films using tiny crystals known as “nanobinders.” These nanobinders form a consistent layer of bismuth telluride sheets, significantly enhancing both the efficiency and flexibility of the film.

“We created a printable A4-sized film with record-high thermoelectric performance, exceptional flexibility, scalability and low cost, making it one of the best flexible thermoelectrics available,” added Chen.

The manufacturing process combined “solvothermal synthesis,” which produces nanocrystals in a solvent under high temperature and pressure, with “screen-printing” and “sintering” techniques. The screen-printing technique facilitates large-scale film production, while sintering — heating the films to near-melting point — bonds the particles together, creating a resilient and efficient material.

First author Wenyi Chen, a QUT researcher, stressed in the news release that the team’s technique “could also work with other systems, such as silver selenide-based thermoelectrics, which were potentially cheaper and more sustainable than traditional materials.”

“This flexibility in materials shows the wide-ranging possibilities our approach offers for advancing flexible thermoelectric technology,” he added.

Beyond powering wearables, this innovation could lead to advancements in personal thermal management. For instance, body heat could drive a wearable heating, ventilation, and air conditioning system, making such devices even more efficient and integrated into everyday life.

While this breakthrough addresses many existing challenges like high costs and complex manufacturing, it also sets the stage for a new era in energy sustainability and electronic device efficiency.