A thin wearable sits flat on the skin and quietly turns body heat into power. Can this approach help us run devices without batteries?
Researchers’ team at Seoul National University College of Engineering has announced that it has developed a flexible and thin “pseudo-transverse thermoelectric generator”. It claims that this next gen wearable technology is capable of producing electricity from body heat and supplying electricity without batteries.
Thermoelectric generators convert temperature differences into electricity and can be comfortably attached to skin because they are lightweight and flexible. However, when the device is attached flat to the skin, body heat passes directly through the thin film and dissipates into the surrounding air forming a negligible temperature difference. This is a limitation because Thermoelectric generators require a temperature difference between both sides to generate electricity.
Dual substrates for heat control
To redirect the flow of heat the research team proposed a new approach by designing a “dual thermal conductivity substrate”. This substrate incorporates thermally conductive copper nanoparticles into only selected regions of a stretchable silicone (PDMS) substrate, creating areas with varying thermal conductivity within a single substrate.
This method prevents heat escape from the skin by making it flow laterally along the high-thermal-conductivity region, when thermoelectric semiconductors are placed at the boundary between these regions. This forms a noticeable temperature difference on the substrate surface enabling electricity generation even in a thin-film. The technology structurally mimics the conventional transverse thermoelectric effect being the first demonstration of its kind and is named “pseudo-transverse thermoelectric generator”, by the research team.
Wearable power for future devices
The device is produced using an ink-based printing process, making it highly flexible and easy to manufacture. Its design is also scalable, meaning it can be adjusted in size and shape or combined like modular blocks to suit different applications. These features are expected to allow the pseudo-transverse wearable thermoelectric generator to be widely used as a self-powered energy technology for various devices, including smart clothing, health monitoring sensors, and wearable electronics.
