A Flexible Self-Powered Sensor Based on a Interpenetrating Network Structure for Motion Monitoring and Energy Harvesting

Enhancing the electrical output performance remains a significant challenge for flexible piezoelectric nanogenerators (PENGs). In this study, carbon black was incorporated as a nanofiller into electrospun PVDF-HFP and Silk fibroin (SF) fibers to improve the conductivity and reduce charge-transfer losses. Based on these fibers, a composite nanofibrous HFPB/SFB membrane with an interpenetrating network structure was designed and fabricated through dual-nozzle electrospinning technology. Based on the dual effects of filler doping and structural design, the piezoelectric output performance of the HFPB/SFB PENG reached up to 8.23 V, which was significantly higher than that of the HFP/SF PENG and also higher than the sum of the piezoelectric outputs of the individual SFB and HFPB PENGs. The prepared HFPB/SFB PENG could generate a high output of 39.01 V and 2.16 nA, capable of illuminating 9 LEDs simultaneously and powering a small timer. Moreover, the assembled HFPB/SFB sensor was capable of detecting various human motions through conversion of mechanical energy to electrical signals, and it also could achieve remote detection when connected to a Bluetooth module. This research presents an effective strategy for the design and development of PENGs with a unique interpenetrating network structure, demonstrating their potential for applications in external energy collection and integration into wearable electronic systems.