Bionic Interlocking-Structured Polyvinylidene Fluoride/Zinc Oxide-Grafting Barium Titanate for Energy Harvesting and Tire Pressure Monitoring

Abstract

Energy scavenging from irregular human motion and the value-added application for a broad range of pressure sensing are gaining attention in wearable electronics and artificial intelligent systems. Here, we designed a bionic interlocking-structured polyvinylidene fluoride/zinc oxide-grafting barium titanate (PVDF/ZnO-g-BT) piezoelectric nanogenerator (PENG) for energy harvesting from human motion and tire pressure monitoring. First, a two-step hydrothermal method was utilized to align uniformly distributed ZnO nanowires onto the BT surface, forming bionic “sea-urchin” (SU) structured ZnO-g-BT. The ZnO nanowires that aligned on the surface can collaborate to facilitate the deformation of BT and endow the molded PVDF/ZnO-g-BT composites with some figures of merit, such as a fast piezoelectric response of ～61 ms, superior sensing sensitivity of ～130 mv/kPa, and excellent stability. Taking advantage of these, the potential application was explored by mechanical energy harvesting from irregular human motion and tire pressure sensing. The excellent electric performance enabled in-time feedback of various useful signals, directing for human motion and tire pressure monitoring. Due to the universal applicability of polydopamine (PDA) coating on any irregular-shaped matrix and easy fabrication of following hydrothermal growing of ZnO nanowires onto the PDA surface, this micro/nano-structure design method can be extended easily to any other organic or inorganic matrix for advanced applications. Undoubtedly, this work provides a simple structure design perspective toward multifunctional wearable electronics and opens a new avenue for piezoelectric sensing.