Flexible and wearable wristband for harvesting human body heat based on coral-like PEDOT:Tos-coated nanofibrous film

Abstract A flexible and wearable thermoelectric wristband consisting of a poly(3,4-ethylenedioxythiophene):p-toluenesulfonic acid (PEDOT:Tos)-coated nanofibrous film (P-type legs) and a Ag nanoparticle-coated nanofibrous film (N-type legs) is constructed to realize the thermoelectric conversion by harvesting of the human body heat. Here, P-type legs are prepared via low-temperature in-situ interfacial polymerization, and a coral-like structure is formed on nanofiber. The resultant P-type leg exhibits a high electrical conductivity of 24.50 S cm⁻¹ and a Seebeck coefficient of 13.67 μV K⁻¹ at a temperature difference (ΔT) of 30 °C. Meanwhile, the N-type legs are fabricated via facile wet electroless deposition exhibits an electrical conductivity of 100 S cm⁻¹. Thus, the constructed fiber-based wristband comprises of seven pairs of P-N legs, and can generate a maximum voltage of ∼0.18 mV at ΔT = 10 °C between user’s skin and the environment. Meanwhile, power is up to 101.51 pW after swinging the arm for 5 min. This thermoelectric wristband successfully completes the recycling of the human body heat and provides a new strategy for developing textile-based thermoelectric devices and monitoring human intelligence.