Flexible Piezoelectric‐Thermoelectric Coupled Nanofiber Generator for Self‐Powered Multimodal Sensing System

Abstract The current mainstream thermoelectric materials are outstanding in terms of power output performance, but their defects, such as high brittleness and poor bending adaptability, seriously limit their applications in the wearable field. To address this problem, in this study, a nanofiber membrane with a core‐shell structure is constructed using polyvinylidene fluoride‐hexafluoropropylene copolymer (PVDF‐HFP) as the core and bismuth telluride (Bi 2 Te 3 ) as the shell. It not only maintains the performance characteristics of piezoelectricity and thermoelectricity but also shows excellent mechanical flexibility (modulus of elasticity as low as 8.87 MPa) and permeability (water vapor permeability as high as 1235 g m −2 day −1 ), which solves the problem of combining rigidity and flexibility of thermoelectric materials. At the same time, the film is sensitive to pressure changes, generating an open‐circuit voltage of 25 V at a pressure of only 0.5 N and a voltage of 2.4 mV at a temperature difference of 5 K, thus realizing the precise acquisition of pressure and temperature signals. In validation experiments, the film accurately and synchronously monitors the motion state and temperature changes on the surface of human skin. It provides a new technical pathway for realizing multifunctional sensing of electronic skin.