Dual Piezoelectric/Triboelectric Behavior of BTO/SU‐8 Photopatternable Nanocomposites for Highly Efficient Mechanical Energy Harvesting

Abstract

The sustenance of the growing Internet of Things revolution requires suitable self‐powering solutions, which can be appropriately complemented by developing efficient energy harvesting systems. Typically, conventional piezoelectric thin film‐based energy harvesters are not promising due to high cost, low coverage area, and size‐frequency‐power trade‐off. Piezoelectric/triboelectric transduction driven mechanical energy harvesters (MEHs) based on nanocomposites offer better efficiency, cost‐effectiveness, and large‐scale production. Here, % weight ratio‐dependent piezoelectric/triboelectric property analysis, and optimization of Barium Titanate (BTO)/SU‐8 based photopatternable nanocomposite thin films are reported for developing highly efficient MEHs. Further, the performance of the nanocomposite is shown to be enhanced by controlled graphene nano‐platelet doping and ultraviolet (UV) exposure. Elaborate Finite Element Method (FEM) study is performed to support the experimental findings. Finally, three MEH devices are developed based on the optimally prepared variants of the nanocomposite and compared experimentally. A maximum output voltage of ≈3 V and power density of 0.65 µW cm−2 are obtained at 0.75 g and at the resonance frequency of 38 Hz from the graphene doped 20% BTO/SU‐8 based harvester. The prototypes have demonstrated the potential to deliver a regulated output voltage of 3.3 V within 40 s of periodic excitation upon integration with a customized power management unit for powering low‐power electronics.

Bandwidth tunable vibration energy harvester based on hybrid triboelectric-piezoelectric array

“…Therefore, the two mechanisms are widely deployed for scavenging mechanical energy at low frequencies. Researchers also integrate these two harvesting mechanisms [13][14][15][16][17] for increased efficiency.…”