High-performance piezoelectric-energy-harvester and self-powered mechanosensing using lead-free potassium–sodium niobate flexible piezoelectric composites

Abstract

A flexible piezoelectric nanogenerator (PENG) was fabricated based on a new inorganic piezoelectric KNN–BNZ–AS–Fe, which exhibited the great potential in energy harvesting and self-powered mechanosensing.

Performance Enhancement of Flexible Piezoelectric Nanogenerator via Doping and Rational 3D Structure Design For Self‐Powered Mechanosensational System

“…The insets in Figure c,d exhibit an enlarged view of the one pulse of output voltages and currents, demonstrating discernible responses of positive and negative piezoelectric potentials during compression and release. It is apparent that the output signals are reversible, suggesting that the measured outputs indeed come from the compression motions of the PENG rather than any other external sources . Due to the flexibility of the silicone rubber, it is difficult to obtain a perfect cross‐section morphology of the PENG by scanning electron microscopy.…”

“…In this circumstance, no output electrical signal will be detected provided that no external force was acted on the PENG device (Figure S6b, Supporting Information) . When the PENG is subjected to vertical compressive pressure, a piezopotential is created across the bottom and top electrodes in virtue of the broken electrostatic equilibrium state and the altered total polarization in the piezocomposite film . In this manner, external negative and positive free charges will migrate and accumulate at the bottom and top electrodes for the sake of screening the piezoelectric potential, resulting in the production of an electrical signal from the PENG (Figure S6c, Supporting Information).…”

“…Therefore, the self‐powered technique based on nanogenerators has aroused extensive concern, indicating an effective pathway toward energy harvesting . Although triboelectric generator (TENG) is easily flexed by utilizing relatively cheap polymers and can generate high output voltage, their drawbacks, such as lower transferred charges restricted by the phenomenon of air breakdown with the similar device size as the piezoelectric nanogenerator (PENG), cannot be ignored . As a consequence, PENG is still the superior choice for small device applications.…”

“…In general, the output performance of the PENG made from piezocomposite film consisting of flexible matrices (e.g., polydimethylsiloxane (PDMS), silicone rubber) and inorganic piezoelectric fillers is primarily determined by the piezoelectric filler, and more significantly, by the stress transfer ability . In conventional piezocomposite film, the flexible matrix protects the piezoelectric filler during the deformation, and the external mechanical stimulation is not easy to reach the piezoelectric fillers and is largely consumed and assimilated by the flexible matrices.…”

Roll‐to‐Roll (R2R) Production of Large‐Area High‐Performance Piezoelectric Films Based on Vertically Aligned Nanocolumn Forests

“…a) The piezoelectric charge coefficients ( d 33 ), b) relative dielectric constants (ε 33 ), and c) the piezoelectric voltage coefficients ( g 33 ) of both aligned and randomly distributed samples at different concentrations. d) Comparison of d 33 , ε r , and g 33 values of different types of piezoelectric materials (the values obtained in this study are denoted with red and blue stars): (i) ceramics, [ 57–61 ] (ii) PDMS‐based composites, [ 27,33,62–64 ] (iii) PVDF and PVDF‐TrFE based composites, [ 65–67 ] (iv) PVC‐based composites, [ 68 ] (v) epoxy‐based composites, [ 69 ] and (vi) polymers. [ 9,59,61,70 ] e) Power‐density output of both aligned and randomly distributed samples at different concentrations.…”