Advancements and challenges in printed thermoelectrics

Printed thermoelectric materials have emerged as promising candidates for large-scale manufacturing due to their low cost, design flexibility, and tunable microstructures. Advances in ink formulation, printable materials, and printing technologies have enabled the fabrication of a wide range of organic, inorganic, and hybrid thermoelectric materials and devices. Despite these advances, challenges remain, including achieving optimal ink rheology, attaining a high thermoelectric figure of merit, maintaining microstructural uniformity, and ensuring stable generator performance after printing. This review provides a comprehensive overview of recent developments in printed thermoelectric materials and devices. It begins by introducing the fundamentals of the thermoelectric effect, key ink properties, and strategies for ink optimization. The discussion then shifts to material performance across various printing techniques and material classes, outlining approaches for further enhancement. Additional factors, such as post-treatment processes, substrate selection, and electrode design are also explored. Finally, practical applications, including sensors, coolers, energy harvesters, and biomedical devices, are highlighted. By linking ink formulation and device engineering with real-world applications, this review offers a roadmap for advancing the development and deployment of printed thermoelectric technologies.