Thermoelectric device charges itself with body heat

Despite the continued development and commercialization of various wearable electronic devices, such as smart bands, progress with these devices has been curbed by one major limitation: they regularly need to be recharged. However, a new technology developed by a South Korean research team shows significant potential to overcome this limitation for wearable electronic devices.

The Korea Institute of Science and Technology (KIST) has announced that a research team led by director Jin-Sang Kim of the Jeonbuk Institute of Advanced Composite Materials has developed a high-efficiency flexible thermoelectric device that is capable of autonomously generating some of the electricity required for its operation from body heat. The device features enhanced thermal insulation capabilities, made possible through the fabrication of the flexible silicone compound (PDMS) into a sponge-like configuration. The newly formed PDMS was then used as a framework for enhancing the device’s performance. 

Thermoelectric devices are able to generate electricity by utilizing the difference in temperature between the two ends of the device and have been used as eco-friendly generators of power from sources such as vehicle engine heat or waste heat from power plants. 

Conversely, by instead applying electricity to the thermoelectric device, one end of the device can be cooled while the other generates heat, enabling them to also be used in temperature control systems for small refrigerators, vehicle cooling sheets and semiconductor equipment.

Normal thermoelectric devices commonly have a rigid ceramic substrate supporting the thermoelectric semiconductor, making them difficult to use on curved surfaces. But in flexible thermoelectric devices, a polymer material encapsulates the thermoelectric semiconductor allowing the device to be bent easily. 

“If we used a sufficient number of thermoelectric devices, it should certainly be possible to produce smart bands that operate on body heat alone,” Jin-Sang Kim said. 

Source: National Research Council of Science and Technology