The benefits of combining 1D and 3D nanofillers in a piezocomposite nanogenerator for biomechanical energy harvesting.

Abstract

Mechanical energy harvesting using piezoelectric nanogenerators (PNGs) offers an attractive solution for driving low-power portable devices and self-powered electronic systems. Here, we designed an eco-friendly and flexible piezocomposite nanogenerator (c-PNG) based on H2(Zr0.1Ti0.9)3O7 nanowires (HZTO-nw) and Ba0.85Ca0.15Zr0.10Ti0.90O3 multipods (BCZT-mp) as fillers and polylactic acid (PLA) as a biodegradable polymer matrix. The effects of the applied stress amplitude, frequency and pressing duration on the electric outputs in the piezocomposite nanogenerator (c-PNG) device were investigated by simultaneous recording of the mechanical input and the electrical outputs. The fabricated c-PNG shows a maximum output voltage, current and volumetric power density of 11.5 V, 0.6 μA and 9.2 mW cm-3, respectively, under cyclic finger imparting. A high-pressure sensitivity of 0.86 V kPa-1 (equivalent to 3.6 V N-1) and fast response time of 45 ms were obtained in the dynamic pressure sensing. Besides this, the c-PNG demonstrates high-stability and durability of the electrical outputs for around three months, and can drive commercial electronics (charging capacitor, glowing light-emitting diodes and powering a calculator). Multi-physics simulations indicate that the presence of BCZT-mp is crucial in enhancing the piezoelectric response of the c-PNG. Accordingly, this work reveals that combining 1D and 3D fillers in a polymer composite-based PNG could be beneficial in improving the mechanical energy harvesting performances in flexible piezoelectric nanogenerators for application in electronic skin and wearable devices.