Fiber‐Based Thermoelectric Generators: Materials, Device Structures, Fabrication, Characterization, and Applications

Abstract Fiber‐based flexible thermoelectric energy generators are 3D deformable, lightweight, and desirable for applications in large‐area waste heat recovery, and as energy suppliers for wearable or mobile electronic systems in which large mechanical deformations, high energy conversion efficiency, and electrical stability are greatly demanded. These devices can be manufactured at low or room temperature under ambient conditions by established industrial processes, offering cost‐effective and reliable products in mass quantity. This article presents a critical overview and review of state‐of‐the‐art fiber‐based thermoelectric generators, covering their operational principle, materials, device structures, fabrication methods, characterization, and potential applications. Scientific and practical challenges along with critical issues and opportunities are also discussed.