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

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. Biomimetic jagged micropatterns templated from photoswitchable liquid crystal polymer network topographies have been demonstrated for triboelectric energy harvesting and wearable sensing applications.