A new groundbreaking technology has been developed that enhances the efficiency of thermoelectric materials, critical in converting waste heat into electricity, by altering their geometry to resemble an hourglass shape. Previous research focused on enhancing the material properties of thermoelectric substances, but this new approach, developed by a joint research team led by Professor Jae Sung Son of POSTECH and Saniya LeBlanc of George Washington University, shows promise in significantly improving power generation efficiency across various applications. Thermoelectric technology is gaining attention as a sustainable and renewable energy source that converts heat from various sources into electricity.
Traditionally, thermoelectric materials have been limited to cuboid shapes, but the research team successfully utilized geometric design and 3D printing processes to create a new geometry for these materials. By simulating various geometric structures and measuring power generation efficiency, the team found that the hourglass shape consistently outperformed others under all conditions. Additionally, the team advanced 3D printing processes to produce thermoelectric materials with high-density micro-layered defects that minimized thermal conductivity and increased the thermoelectric performance index (ZT) to 2.0, the highest achieved via 3D printing for thermoelectric materials.
The team further fabricated thermoelectric generators using different structures and found that the hourglass-shaped generator was around 3.6 times more efficient than the traditional rectangular-based generator. Professor Jae Sung Son noted that this research marks the first instance where efficiency has been improved through three-dimensional geometry control of thermal and electrical transport, rather than focusing solely on material microstructure. This new approach is expected to be universally applicable to all thermoelectric materials and could also be utilized in thermoelectric cooling technologies.
This achievement was made possible with support from the Mid-Career Researcher Program and Nano and Materials Technology Development Program under the Ministry of Science and ICT and the National Research Foundation of Korea. The research findings were published online in the international journal Nature Energy on July 19. The success of this research opens up new possibilities for enhancing the efficiency of thermoelectric materials and generators, potentially enabling widespread applications in various industries and everyday use. As thermoelectric technology continues to be developed as a sustainable energy source, this new approach to improving power generation efficiency through geometric design and 3D printing processes could revolutionize the field and contribute to the advancement of renewable energy solutions.