Review of Zinc Oxide Piezoelectric Nanogenerators: Piezoelectric Properties, Composite Structures and Power Output

Abstract

Lead-containing piezoelectric materials typically show the highest energy conversion efficiencies, but due to their toxicity they will be limited in future applications. In their bulk form, the piezoelectric properties of lead-free piezoelectric materials are significantly lower than lead-containing materials. However, the piezoelectric properties of lead-free piezoelectric materials at the nano scale can be significantly larger than the bulk scale. This review looks at the suitability of ZnO nanostructures as candidate lead-free piezoelectric materials for use in piezoelectric nanogenerators (PENGs) based on their piezoelectric properties. Of the papers reviewed, Neodymium-doped ZnO nanorods (NRs) have a comparable piezoelectric strain constant to bulk lead-based piezoelectric materials and hence are good candidates for PENGs. Piezoelectric energy harvesters typically have low power outputs and an improvement in their power density is needed. This review systematically reviews the different composite structures of ZnO PENGs to determine the effect of composite structure on power output. State-of-the-art techniques to increase the power output of PENGs are presented. Of the PENGs reviewed, the highest power output belonged to a vertically aligned ZnO nanowire (NWs) PENG (1-3 nanowire composite) with a power output of 45.87 μW/cm2 under finger tapping. Future directions of research and challenges are discussed.

Hierarchical Wrinkles with Piezopotential Enhanced Surface Tribopolarity for High-Performance Self-Powered Pressure Sensor

“…Considering that the contact electrification process both in polarity and magnitude of the charge transfer can manipulate through an applied electric field between two materials, 34 hence, building up an electric field inside TPS may be a promising way to further incorporate with existing strategies to enhance the comprehensive performance of TPS. Over the past decade, ZnO has been extensively studied as a piezoelectric material for applications of piezoelectric nanogenerators, 35 and a maximum output voltage of more than 50 V was realized. 36 Considering the merits of good piezoelectric properties, and easy growth of nanowires and other nanostructures on multiple substrates, 37 ZnO is an ideal choice to simultaneously establish an electric field inside the TPS (electrical effect) and structuralize its sensing layer.…”

“…Over the past decade, ZnO has been extensively studied as a piezoelectric material for applications of piezoelectric nanogenerators, and a maximum output voltage of more than 50 V was realized . Considering the merits of good piezoelectric properties, and easy growth of nanowires and other nanostructures on multiple substrates, ZnO is an ideal choice to simultaneously establish an electric field inside the TPS (electrical effect) and structuralize its sensing layer.…”

A Data Mining Study of Zinc Oxide Nanostructures Utilization in Drug Delivery Nanosystems

“…[58,59] Moreover, ZnO NPs exhibit distinctive physicochemical attributes, including robust piezoelectric and pyroelectric properties, rendering them responsive to mechanical and thermal variations. [60][61][62][63][64] These attributes could be harnessed in advanced DDSs designed to respond to specific physiological changes. Furthermore, their pronounced ultraviolet absorption and visible light emission capacities offer avenues for imaging applications, facilitating precise tracking of drug distribution within the body.…”

Enabling electrical response through piezoelectric particle integration in AA2017-T451 aluminium parts using FSP technology

“…Recent progress in piezoelectric materials and manufacturing methods at the micro and nanoscale have broadened the application fields of piezoelectric technology. Materials like ceramics [23,24], polymers [25,26], composites [27,28], and biocompatible materials [5,29], in diverse nanostructures [30,31] and thin films [32,33], exhibit satisfactory physical properties such as high piezoelectric coefficients, flexibility, stretchability, and durability. This study explores the principles of piezoelectricity and the choice of materials, emphasizing the role of piezoceramics and piezoelectric composites in SHM.…”