The schematics of flexible thermoelectric fibers including thermally drawn fiber technology, crystal structures of fiber cores (amorphous thermoelectric fiber, polycrystalline thermoelectric fiber, single crystal thermoelectric fiber and plasticity thermoelectric fiber), and wearable fabric applications (temperature sensor, thermoelectric cooling, thermoelectric generation and superflexible thermoelectric fabric). The map element in the figure was modified with permission from Refs. [3–5].