“…The rapid development of flexible and wearable electronics puts forward high requirements for wearable power supply systems. − Thermoeletric (TE) devices, which can harvest energy from the human body heat and convert it into electric power, have gained considerable attention because they can be used to provide energy for wearable devices sustainably and uninterruptedly. − To realize flexible and wearable application, various fiber-based TE devices were designed and prepared due to their advantages of flexibility, wearing comfort, and designable structure. Based on former studies, most fiber-based TE devices are obtained by combining fabrics with various TE materials, such as the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), poly(3-hexylthiophene) (P 3 HT), PbTe, Sb 2 Te 3 , and Bi 2 Te 3 . − Compared with the brittle inorganic TE materials, the use of conducting polymers such as PEDOT, polythiophene (PTh), and polypyrrole (PPy) as coating layers to construct fiber-based TE devices offers numerous advantages of great flexibility, light weight, and low thermal conductivity. − Typically, PEDOT:PSS is the most commonly used organic TE material, which has high electrical conductivity, water solubility, and easy processability. , …”