Printed Organic Thermoelectric Generators: Progress and Challenges Towards Efficient Energy Harvesting

ABSTRACT Printed organic thermoelectric generators (OTEGs) represent a rapidly advancing class of flexible and sustainable energy harvesting devices capable of converting low‐grade heat into electrical energy. This Perspective highlights recent progress in printable thermoelectric materials, device architectures, and the development of 2D and 3D printed OTEGs. Despite notable improvements, the power output of printed OTEGs typically remains below 100 nW cm ⁻² , with the best devices reaching up to 48 µW cm ⁻² under moderate temperature differences. The Perspective also discusses emerging efforts toward green processing, biodegradable substrates, and solvent‐free formulations that minimize environmental impact and electronic waste. Finally, future directions are outlined for developing high‐performance, recyclable, and hybrid thermoelectric systems integrated with other energy harvesting technologies, paving the way toward fully sustainable and autonomous wearable electronics.