Flexible Pressure Sensor Based on Highly Oriented PVDF/ZnONRs@Ag Electrospun Fibers for Directional Sensing

In recent years, research on piezoelectric pressure sensing has attracted worldwide attention, as eagerly demanded by the development of wearable electronics. However, the current piezoelectric pressure sensors are unable to detect forces along different bending directions with a high resolution, thus limiting their applications in some typical scenarios. To address this issue, this study designed a novel composite structure with ZnO nanorods loaded with Ag nanoparticles (ZnONRs@Ag) and then embedded in highly oriented polyvinylidene fluoride (PVDF) fibers. Due to its unique orientation, the pressure sensor exhibits anisotropy, accurately identifying forces along distinct bending directions (such as perpendicular, parallel, or twisting). The optimized PVDF/ZnONRs@Ag device presents the peak power density of 308.1 nW cm^-2 and a sensitivity as high as 0.52 V N^-1 and remains stable after 7000 cycles at 1.4 Hz. The highly oriented piezoelectric devices are utilized to monitor various human movements and harvest energy from them. This research provides a viable method for manufacturing self-powered directional pressure sensors, contributing to the advancement of wearable technology and energy harvesting applications.