High-Performance Lightweight and Flexible PVDF-B/MXene/Chitosan Composite Aerogel for Sensitive Self-Powered Sensing

Piezoelectric devices are becoming increasingly attractive in areas such as wearable electronics, mobile environmental sensors, and health monitoring due to their unique capability to harvest discrete mechanical energy. Nevertheless, most piezoelectric materials are fabricated into low-dimensional products, which limits the performance breakthroughs and application prospects of these devices. Here, a series of polyvinylidenefluoride (PVDF) doped with dopamine hydrochloride@BaTiO3/MXene/chitosan (PVDF-B/MXene/CS) composite aerogel piezoelectric devices with outstanding output performance were fabricated by combining electrospinning and freeze-drying techniques. Among them, the PVDF-B/MXene/CS composite aerogel-based piezoelectric devices with electrodes exhibited rather better output performance compared to those without electrodes, while the electrodeless piezoelectric devices demonstrated excellent piezoelectric response under various stress modes. The electrodeless piezoelectric devices maintained a stable voltage over 1800 cycles and achieved the maximum power output of 4.25 nW with an external resistance of 100 MΩ. Furthermore, the electrodeless piezoelectric device was capable of charging capacitors with varying capacities and could easily illuminate a small light emitting diode (LED) light by manual tapping. These piezoelectric devices showed tangible and stable signals regarding mechanical stimuli monitoring, such as wrist bending, finger tapping, and pedal movements. This work not only expands the range of aerogel-based piezoelectric materials but also showcases their immense potential in the field of piezoelectric devices.