A Novel Thin-Film Technology for Body-Powered Electronics

A research team led by the Queensland University of Technology (QUT) has developed an ultra-thin, flexible film that, according to a study published in Science, could power next-generation wearables using body heat instead of batteries.

This method could also be applied to cool electronic chips, helping computers and smartphones function more efficiently.

Professor Zhi-Gang Chen explained that the innovation addresses a major challenge in developing flexible thermoelectric devices that convert body heat into energy.

This approach has the potential to offer a sustainable energy source for wearable electronics, as well as an effective cooling solution for electronic chips.

Along with Professor Chen, QUT researchers contributing to the study include first author Mr. Wenyi Chen, Dr. Xiao-Lei Shi, Dr. Meng Li, Mr. Yuanqing Mao, and Miss Qingyi Liu, all from the ARC Research Hub in Zero-emission Power Generation for Carbon Neutrality, the QUT School of Chemistry and Physics, and the QUT Center for Materials Science.

The research team also includes Mr. Ting Liu, Professor Matthew Dargusch, and Professor Jin Zou from the University of Queensland, as well as Professor Gao Qing (Max) Lu from the University of Surrey.

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. They could also be applied in a tight space, such as inside a computer or mobile phone, to help cool chips and improve performance. Other potential applications range from personal thermal management–where body heat could power a wearable heating, ventilating and air conditioning system. However, challenges like limited flexibility, complex manufacturing, high costs, and insufficient performance have hindered these devices from reaching commercial scale.

Zhi-Gang Chen, Professor, Queensland University of Technology

Most research in this area has focused on bismuth telluride-based thermoelectrics, which are valued for their ability to convert heat into energy. This makes them ideal for low-power applications like heart rate, temperature, and movement monitors.

In this study, the team developed a cost-effective method for creating flexible thermoelectric films by using small crystals, or "nanobinders," that form a continuous layer of bismuth telluride sheets, improving both efficiency and flexibility.

Chen added, “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.”

The team combined "solvothermal synthesis," which produces nanocrystals in a solvent under high temperature and pressure, with "screen-printing" and "sintering." Screen-printing allows for large-scale film fabrication, while sintering heats the films to near-melting temperatures, fusing the particles together.

Mr. Wenyi Chen stated that their technology might also be used with other systems, such as silver selenide-based thermoelectrics, which could be less expensive and more sustainable than previous materials.

This flexibility in materials shows the wide-ranging possibilities our approach offers for advancing flexible thermoelectric technology.

Wenyi Chen, Study First Author, School of Chemistry and Physics, Queensland University of Technology

Video Credit: Queensland University of Technology

Journal Reference:

Chen, W., et. al. (2024) Nanobinders advance screen-printed flexible thermoelectrics. Science. doi.org/10.1126/science.ads5868