Researchers at the Queensland University of Technology (QUT) have developed an ultra-thin, flexible film capable of converting body heat into electrical energy.
This breakthrough is a significant advancement in the field of wearable technology. It has the potential to revolutionize the way we power wearable devices.
“This technology could also be used to cool electronic chips, helping smartphones and computers run more efficiently,” read a press release.
“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,” said Professor Zhi-Gang Chen, who led the research team.
However, several challenges have hindered these devices from reaching commercial scale. These include limited flexibility, complex manufacturing, high costs, and insufficient performance.
Overcoming challenges in flexible thermoelectrics
The QUT team overcame this hurdle by employing a novel approach that combines the thermoelectric properties of bismuth telluride with the structural benefits of tellurium nanorods.
Bismuth telluride is a well-known thermoelectric material, but its inherent rigidity has limited its use in flexible applications.
The researchers solved this problem by adding tellurium nanorods to the material. These nanorods function as “nanobinders,” filling the spaces between the bismuth telluride sheets and creating a network.
This structure increases the film’s ability to convert heat into electricity and gives it flexibility.
Evaluation of the film’s performance
The research team conducted tests to evaluate the performance of the film. They made a small-scale generator from an A4-sized sheet of the film and equipped it with silver paste electrodes connected to measuring equipment.
“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,” highlighted Professor Chen.
When placed against the skin, the generator produced a noteworthy 1.2 milliwatts of power per square centimeter with a temperature difference of 20 Kelvin between the skin and the surrounding air.
This level of power generation, readily achievable under typical ambient conditions, underscores the potential of this technology for powering a wide range of wearable devices.
Applications beyond wearable technology
The implications of this research extend beyond wearable technology. The team also demonstrated the film’s ability to cool electronic chips, a critical aspect of maintaining optimal performance in electronic devices.
By reversing the energy conversion process, they achieved a temperature reduction of 11.7 Kelvin with a minimal input current.
“This flexibility in materials shows the wide-ranging possibilities our approach offers for advancing flexible thermoelectric technology,” Chen said.
“They could also be applied in a tight space, such as inside a computer or mobile phone, to help cool chips and improve performance.”
While the team is enthusiastic about the potential of their work, they acknowledge that further research and development are necessary.
“This strategy should work for other materials and provides a way to produce large-scale, flexible thermoelectrics,” concluded the study.
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