Biomimetic jagged micropatterns templated from photoswitchable liquid crystal topography for energy harvesting and sensing applications

Abstract

In this study, an ingenious approach is developed using a fluorocarbon polymer tribosurface with jagged relief patterns, templated from the surface topographic microstructure of a photoresponsive liquid crystal polymer network (LCN), to significantly enhance the output performance of a triboelectric nanogenerator (TENG). The obtained photoresponsive polydomain LCN, which can generate jagged patterns (i.e. large 3D spikes) at the polymer surface by UV light irradiation, is exploited as a robust and reusable master mold to fabricate jagged patterns at a fluorocarbon polymer coating. Then, the fluorocarbon polymeric coating with jagged topographies is employed to construct a vertical contact-separation-mode TENG (FC-TENG). Owing to the fluorocarbon material selection and roughened morphologies of the tribosurface layer, the open circuit voltage and short circuit current of FC-TENG increased from 106.7 V, 0.69 μA to 194.9 V, 1.28 μA compared to TENG without the surface microstructure under the condition of 10 N force and 4 Hz contact separation frequency. Moreover, a self-powered LC device and wearable electronic sensor using an FC-TENG are demonstrated. This work may provide a new route for the fabrication of microstructured surfaces, rendering triboelectric energy harvesting more efficient.