TEGNet: AI That Freely Designs Thermoelectric Devices

Toward realizing a sustainable society, thermoelectric generation technology capable of generating power indefinitely merely by installing a device at any place with temperature differences is drawing attention. In order to improve performance of thermoelectric generators, not only material development, but also optimal design of dimensions and structure are indispensable. However, conventional numerical analysis (finite element method) had a problem of requiring computation to be repeated whenever conditions were changed, which caused heavy computational load and made large-scale and high-speed design exploration difficult.

In order to solve this problem, the research group developed TEGNet, an AI model capable of optimizing the design of thermoelectric generators at high speed. If material properties and element dimensions and conditions are input into TEGNet, TEGNet quickly predicts voltage and heat flow that are generated within the device, making it possible to estimate power generation output and conversion efficiency at high accuracy (Figure). The most notable feature of this technology is in its composability, which allows designers to freely combine independent TEGNet models that have been trained for each material, like blocks, based on the laws of physics. This approach can enable designers to speedily and exhaustively explore and optimize performance, even for a device with a complex structure that combines materials having different properties. To demonstrate this approach, the team optimized two types of device designs using Mg-Sb (magnesium-antimony) based materials, prototyped and evaluated those devices, and achieved high conversion efficiencies of up to 9.3% and 8.7% under practical temperature conditions.

This research result proposes a next-generation design technique using AI as core technology, as opposed to conventional thermoelectric generator design dependent on numerical simulations. While many AI studies have focused on material-level optimization in recent years, the key feature of this research is that it directly targets device-level optimization. As a result, it becomes possible to sophisticate material design and device design in a complementary manner, and AI utilization is expected to develop further not only in the thermoelectric field, but in the entire energy field.

• This project was conducted by a research team led by Takao Mori (Group Leader, Thermal Energy Materials Group, Nanomaterials Field, Research Center for Materials Nanoarchitectonics (MANA), NIMS). The work was supported by the Japan Science and Technology Agency (JST), JST-Mirai Program Large-Scale Type, technology theme: “Innovative thermoelectric conversion technologies for stand-alone power supplies for sensors” (Project Leader: Takao Mori).
• This research result was published online in Nature at 11:00 U.S. Eastern Standard Time, April 15, 2026 (0:00 Japan Standard Time, April 16, 2026).