Piezoelectric Nanogenerators Derived Self‐Powered Sensors for Multifunctional Applications and Artificial Intelligence

Abstract

With the arrival of the Internet of Things (IoTs) era, there is a growing requirement for systems with many sensor nodes in a variety of fields of applications. The demands for wireless, sustainable and independent operation are becoming more and more important for large‐scale sensor networks and systems. For these purposes, a self‐powered sensory system that can utilize the self‐harvested energy from its surroundings to drive the sensors and directly sense external stimuli has attracted great attention. The invention and rapid development of piezoelectric generators (PENGs), which take Maxwell's displacement current as the driving force, has been pushing forward research on self‐powered active mechanical sensors, electronic skins, and human‐robotic interaction. Here, this review starts with a brief introduction of piezoelectric materials, fabrication, and performance improvement. Then, the energy harvesters used for self‐power systems based on recent progress are reviewed. After that, PENGs applications toward recent self‐powered active sensors are divided into four aspects and highlighted, respectively. Moreover, some challenges and future directions for the self‐powered multifunctional sensors are put forward. It is believed that through the continuous investigations into PENG‐based self‐powered active sensors, they will soon be used in touch screens, electronic skins, health care, environmental monitoring, and intelligence systems.

Engineering the Defects and Microstructures in Ferroelectrics for Enhanced/Novel Properties: An Emerging Way to Cope with Energy Crisis and Environmental Pollution

“…The BaTiO 3 nanowire arrays were caped with top electrodes for piezoelectric energy harvesting. [101,102] Zhang et al [103] have reported a topochemical x and y axes represent the [100] and [010] crystallographic directions, respectively, the color bar denotes the angle between the polar vector of the grids and the [100] direction. Reproduced with permission.…”

“…Figure 10. a) Microstructures for a [100]-poled PNR-ferroelectric composite at 100 K obtained by phase-field-simulation. b) Enlarged area of (a) with polar vectors.x and y axes represent the[100] and [010] crystallographic directions, respectively, the color bar denotes the angle between the polar vector of the grids and the[100] direction. Reproduced with permission [97].…”

Electromechanical conversion efficiency of GaN NWs: critical influence of the NW stiffness, the Schottky nano-contact and the surface charge effects

“…[1][2][3][4][5] In particular, NWs presenting piezoelectric properties appear as promising active nanostructures for a new generation of piezoelectric sensors [6][7][8][9][10] and harvesters. [11][12][13][14][15] Especially, the sub-100 nm-wide NWs present the particularity to exhibit novel properties, non-existing or non-significant at micrometric scales that can lead to a strong modulation/modification of their characteristics. The exaltation of the piezoelectric coefficients, [16][17][18] the modulation of the free carrier concentration 19,20 or the formation of nano-contact at the NW/ electrode interface 21 are examples of these nanoscale phenomena.…”

Dynamic Schottky Diode Direct‐Current Generator under Extremely Low Temperature

“…In recent years, with the rapid development of nano-processing technology, various high-performance miniaturized sensors and devices are proposed in every field of Internet of Things. [1,2] A large part of these nanodevices is distributed in the areas far away from cities or even in extremely low temperature conditions, [3] where the energy is supplied by battery which is costly and environmentally unfriendly. [4,5] As an alternative solution to this challenge, harvesting energy directly from the environment attracts increasing attention recently and a lot of attempts have been made to obtain electricity output with various kinds of generators through utilizing different kinds of power including mechanical energy, [6][7][8] hydraulic energy, [9][10][11] solar energy, [12][13][14] Typical voltage and current responses to the moving of the Cu film along the p-type Si surface are shown in Figure 1c-f.…”