“Body temperature is the source of energy” KAIST develops wearable thermoelectric element

A wearable thermoelectric element with both elasticity and high performance has been developed. Thermoelectric devices are attracting attention as an eco-friendly and sustainable energy platform in that they can convert thermal energy into electricity and utilize discarded waste heat. The developed technology is a wearable device that uses body heat, and is expected to be used as a key technology in implementing a next-generation energy supply platform.

KAIST announced on the 14th that Professor Hongcheol Moon’s team in the Department of Biological and Chemical Engineering and Professor Taeho Park’s team in the Department of Chemical Engineering at POSTECH have implemented technology to overcome the performance limitations of existing N-type thermoelectric galvanic devices through thermodynamic balance control.

Thermoelectric galvanic devices can be divided into ‘N-type’ and ‘P-type’ depending on the direction of electron flow. N-type, which means negative, means electrons move from low temperature to high temperature, and P-type, which means positive, means electrons move from high temperature to low temperature.

In order to maximize the performance of thermoelectric elements, integration of N-type and P-type elements is essential. However, while research on P-type thermoelectric devices was mainly conducted, research on N-type thermoelectric devices was relatively lacking.

Even so, N-type thermoelectric devices have lower performance than P-type devices, so when implementing integrated devices, the balance is not right, which is an obstacle to maximizing performance.

To solve this problem, the joint research team developed a gel material capable of controlling its acidity (pH) and implemented a thermoelectric galvanic device, a type of ionic thermoelectric device that uses ions as the main charge carrier.

In addition, the developed gel material is used to effectively control the thermodynamic equilibrium of the redox (oxidation-reduction reaction) reaction of hydroquinone (an electrochemical reactant used to convert thermal energy into electrical energy), thereby achieving high-performance N-type thermoelectric device characteristics. succeeded in bringing out

In particular, the gel material developed by the joint research team was designed to achieve excellent elasticity of 1700% and self-healing performance of more than 99% within 20 minutes even at room temperature based on reversible cross-linking.

Reflecting this, the N-type ionic thermoelectric element achieves a high thermopower of 4.29 mV K-1 and at the same time has a Carnot relative efficiency of 1.05% (the actual heat conversion efficiency of the thermoelectric galvanic element compared to the efficiency of the ideal Carnot engine). ), the joint research team emphasized.

Ultimately, the device attached to the wrist succeeded in effectively producing energy by using the temperature difference between the body temperature maintained in the body and the temperature of the surrounding environment.

Professor Hongcheol Moon said, “The significance of this research is that we have developed technology to overcome the limitations of the existing N-type ionic thermoelectric system,” adding, “This will accelerate the commercialization of power systems using body heat and provide the key to driving wearable devices.” “We expect it to become an essential technology,” he said.

<ⓒ투자가를 위한 경제콘텐츠 플랫폼, 아시아경제(www.asiae.co.kr) 무단전재 배포금지>