Ink-Printed Thermoelectric Materials and Devices: Material Preparation, Fabrication Techniques, and Applications

Thermoelectric (TE) materials, which enable the direct conversion between thermal and electrical energy, represent a promising solution for sustainable energy technologies. While significant improvements in the figure of merit (ZT) have been achieved over the past two decades, a pressing need remains for scalable synthesis and flexible manufacturing methods to fabricate high-performance devices. Additive manufacturing via printing provides precise geometric control and scalability for fabricating high-performance TE devices. The properties of these printed devices are largely determined by the TE inks employed. This review systematically summarizes recent progress in TE inks, focusing on three key areas: material preparation, including TE ink formulation and binding strategies; processing techniques, such as inkjet printing and screen printing; and applications, highlighting advanced printed TE devices for energy harvesting, thermal management, and sensing. Given recent progress, this review establishes a framework for future development of printed TEs. Finally, we discuss emerging research and applications, opportunities, and suggest that the fundamental principles of TE ink development could find broader applications in biomedical fields such as tissue repair and disease treatment.