摘要
Wearable devices for real-time health monitoring face significant challenges due to their sensitivity, long response time and reliance on external power sources. Herein, we present a hierarchical interlock-structured piezoelectric sensor designed with flexible stacked microstructures, composed of an electrospun polyvinylidene fluoride–graphene oxide/polyvinylidene fluoride–barium titanate (PVDF-GO/PVDF-BTO) nanofibrous membrane and Au-sprayed double-sided, bioinspired superhydrophobic PDMS electrodes. These components provide the device with superhydrophobic outer surface (contact angle of ∼160°) and multisensory capabilities, allowing for simultaneous pressure and stretch sensing with high sensitivity (367 mV kPa −1 ), low detection limit (800 Pa), broad operational range (up to 100 kPa), rapid response and recovery times (26 ms and 22 ms, respectively), and remarkable stability (5000 cycles). The sensitivity benefits from the unique design of the piezoelectric hierarchical nanofibrous membrane with manifold microstructures interlocked by electrodes with microdome arrays, enabling large-range deformation at multipoint contacts between sensing layer and electrode under different level of applied pressure, thereby generating sufficient amount of electric power to indicate slight difference in pressure and stretching. A robust electrospinning process combined with hollow-carved template stacking demonstrates that various microstructure geometries, such as microsquares, microcolumns, and microgrooves and dimensions of these structures can be precisely tuned to optimize the electrical performance of the piezoelectric sensor. This work proposes a cost-effective tunable approach to fabricating flexible sweat-resistant sensors with significant potential for precise joint movement tracking and physiological signal detection in physical rehabilitation and self-powered healthcare.
危险品化学品经营许可证（带存储）