Emerging Trends in Additive Manufacturing for Thermoelectric Devices: Materials, Structures, and Engineering Approaches.

Energy harvesting is gaining importance in the 21st century, with thermoelectric (TE) technology offering a promising method for converting thermal energy into electrical energy. However, the application of TE devices remains relatively low because of the limitations of conventional manufacturing methods. Fabricating complex-shaped TE devices using traditional manufacturing processes is challenging and leads to a low efficiency. Unlike conventional subtractive methods, additive manufacturing (AM) builds three-dimensional (3D) objects layer by layer, enabling the creation of intricate and complex structures with precision. This study explores recent trends in AM of thermoelectric systems, with a focus on materials, synthesis methods, and device fabrication. It also discusses the challenges associated with these AM techniques and explores potential areas for improvement. Recent studies have shown that AM can produce thermoelectric units with hollow and layered structures, enhancing temperature gradients and power density compared with conventional designs. The ability to customize geometries through AM offers promising opportunities to enhance the performance of the TE materials and devices. AM technologies can produce highly efficient, functionally graded TE devices. By enabling rapid prototyping and high-performance structures, AM can improve the efficiency and application of the TE materials. Future work focuses on further advancing these AM techniques by integration with machine learning (ML) and development of multimaterial TE devices.