Rational design of stretchable and highly aligned organic/inorganic hybrid nanofiber films for multidirectional strain sensors and solar-driven thermoelectrics

Electrospinning technology is an effective and simple approach to prepare nanofiber films, which has been widely used in the wearable electronics based on energy harvesting. However, their application in the field of thermoelectrics is rarely reported mainly due to the ultralow performance and difficulty in maintaining temperature difference. Herein, we have designed highly aligned organic/inorganic hybrid nanofiber films with excellent stretchability and thermoelectric performance via electrospinning technology and surface coating methods. The aligned structure is beneficial to fast carrier transportation, in which a sevenfold increase in power factor is achieved as compared with the random structure. Additionally, novel radiative-cooling photothermal-heating electrodes are successfully designed to fabricate solar-driven thermoelectric generators based on the unique aligned nanofiber structure, providing a new concept to build in-plane temperature difference for ultrathin-film-based thermoelectrics. Furthermore, two highly aligned organic/inorganic hybrid nanofiber films are stacked orthogonally to assemble multidirectional strain sensors, which can distinguish the complex motion of human joints. These findings will inspire the future development and application of electrospun nanofiber-based thermoelectrics in the next-generation wearable electronics.