Charge generation from as-electrospun polystyrene fiber mat with uncontacted/contacted electrode

Abstract

Micrometer/submicrometer electromechanical polymer fibers are promising components for wearable pressure sensors and energy harvesters because of their high mechanical flexibility, low weight, and excellent breathability. Recently, the excellent electromechanical properties of mats of the as-electrospun micrometer/submicrometer polymer fibers have been reported; however, these devices have a contacting electrode/fiber mat/electrode structure. In this study, the electrical output properties of an as-electrospun polystyrene fiber mat with one electrode not in contact and/or in contact with the fiber mat were theoretically and experimentally investigated. The electric charges were output when the uncontacted electrode approached the fiber mat, and the amount of electric charges increased monotonically during the approach even after the electrode contacted the fiber mat and indented. The amount of electric charges was determined using theoretical functions. At the maximum displacement of the electrode, the average maximum output voltage had an absolute value of 2.28 ± 0.04 V when using the electrode with an area of 5.0 × 10−5 m2, a load of 10.1 MΩ, and a displacement time of approximately 15 ms. These experimental and theoretical findings can pave the way for the development of soft, lightweight, and breathable wearable pressure sensors and energy harvesters from a variety of materials and unique structures.