The thermoelectric device converts energy using the voltage produced by the temperature difference between the two ends of the material - it is able to convert thermal energy into electricity, which can be used in everyday life. The existing thermoelectric devices are rigid, since they consist of electrodes based on solid metals and semiconductors, which prevents the full absorption of heat sources from uneven surfaces. Therefore, recently research is actively conducted on the development of flexible thermoelectric devices that can produce energy in close contact with various heat sources, including those like human skin.
Scientists from the Korean Institute of Science and Technologies (KIST) have developed subtle and flexible thermoelectric devices with high energy characteristics due to the maximum flexibility and heat transfer efficiency. The developers also presented a mass production plan using an automated workflow comprising a printed process.
According to Korean scientists,
These studies have shown that with the help of external heat sources, you can work with existing weares, such as high-temperature gloves. In the future, we will develop a flexible thermoelectric platform that will be able to work with wearase devices, getting energy only due to heat of the body.
Functional composite material, the thermoelectric device platform and a high-performance automated process developed under this study will be able to promote the commercialization of wearable devices that do not require batteries in the future.
As for the existing substrates used for studies of flexible thermoelectric devices, their thermal energy transmission efficiency is low due to very low thermal conductivity. Their effectiveness of heat-absorption is also low due to the lack of flexibility forming the heat insulation layer in contact with the heat source consisting of the air. To solve this problem, thermoelectric devices based on organic materials with high flexibility are being developed, however, their use in wearable devices is ineffective due to their significantly more bad characteristics compared with existing rigid thermoelectric devices based on inorganic materials.
The Korean researchers group increased flexibility while reducing the system resistance by connecting a highly efficient thermoelectric device based on inorganic materials to a tensile substrate consisting of silver nanopod. The new device has demonstrated excellent flexibility, thereby providing stable operation even with bending or stretching. In addition, metal particles with high thermal conductivity were inserted inside the tensile substrate, which made it possible to increase heat transfer by 800% (1.4 W / MK) and the generation of electricity than three times.