Stretchable piezoelectric energy harvesters and self-powered sensors for wearable and implantable devices

A self-powered system based on energy harvesting technology can be a potential candidate for solving the problem of supplying power to electronic devices. In this review, we focus on portable and wearable self-powered systems, starting with typical energy harvesting technology, and introduce portable and wearable self-powered systems with sensing functions. In addition, we demonstrate the potential of self-powered systems in actuation functions and the development of self-powered systems toward intelligent functions under the support of information processing and artificial intelligence technologies.

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Portable and wearable self-powered systems based on emerging energy harvesting technology.

The red shift and the broadening of the Raman signal from microcrystalline silicon films is described in terms of a relaxation in the q-vector selection rule for the excitation of the Raman active optical phonons. The relationship between width and shift calculated from the known dispersion relation in c-Si is in good agreement with available data. An increase in the decay rate of the optical phonons predicted on the basis of the same model is confirmed experimentally.

The one phonon raman spectrum in microcrystalline silicon

Piezoelectric Nanogenerator Based on In Situ Growth All-Inorganic CsPbBr3 Perovskite Nanocrystals in PVDF Fibers with Long-Term Stability

This article provides a comprehensive overview of piezo‐ and ferro‐electric materials based on organic molecules and organic–inorganic hybrids for mechanical energy harvesting. Molecular (organic and organic–inorganic hybrid) piezo‐ and ferroelectric materials exhibit significant advantages over traditional materials due to their simple solution‐phase synthesis, light‐weight nature, thermal stability, mechanical flexibility, high Curie temperature, and attractive piezo‐ and ferroelectric properties. However, the design and understanding of piezo‐ and ferroelectricity in organic and organic–inorganic hybrid materials for piezoelectric energy harvesting applications is less well developed. This review describes the fundamental characterization of piezo‐ and ferroelectricity for a range of recently reported organic and organic–inorganic hybrid materials. The limits of traditional piezoelectric harvesting materials are outlined, followed by an overview of the piezo‐ and ferroelectric properties of organic and organic–inorganic hybrid materials, and their composites, for mechanical energy harvesting. An extensive description of peptide‐based and other biomolecular piezo‐ and ferroelectric materials as a biofriendly alternative to current materials is also provided. Finally, current limitations and future perspectives in this emerging area of research are highlighted. This perspective aims to guide chemists, materials scientists, and engineers in the design of practically useful organic and organic–inorganic hybrid piezo‐ and ferroelectric materials and composites for mechanical energy harvesting.

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Recent Advances in Organic and Organic–Inorganic Hybrid Materials for Piezoelectric Mechanical Energy Harvesting

Human motion interactive mechanical energy harvester based on all inorganic perovskite-PVDF

https://iopscience.iop.org/article/10.1088/2053-1591/ab87d6/pdf

Dielectric and piezoelectric augmentation in self-poled magnetic Fe3O4/poly(vinylidene fluoride) composite nanogenerators

Magnetite (Fe3O4), a representative relaxor multiferroic material, possesses fundamentally appealing multifaceted size-dependent properties. Herein, to evaluate a prototype spinel transition metal oxide (STMO), monodispersed and highly water-dispersible spherical magnetite nanoparticles (MNPs) with an enormous size range (3.7-242.8 nm) were synthesized via a facile microwave-assisted and polyol-mediated solvothermal approach at a controlled temperature and pressure using unique crystallite growth inhibitors. The excellent long-term colloidal stability of the MNPs in a polar environment and increase in their zeta potential confirmed the coordinative effect of the carboxylate groups derived from the covalent surface functionalization, which was also validated by FTIR spectroscopy, TGA and XPS analysis. The optical bandgap (Eg) between the crystal field split-off bands, which was calculated using the absorption spectra, increased gradually with a decrease in size of the MNPs within a broad UV-Vis range (1.59-4.92 eV). The red-shifting of the asymmetric Raman peaks with a smaller size and short-range electron-phonon coupling could be explained by the modified phonon confinement model (MPCM), whereas ferrimagnetic nature rejigged by superparamagnetism was verified from Mossbauer analysis. These stoichiometric, non-toxic, polar and magnetic nanocrystals are not only ideal for biomedical applications, but also suitable as electroactive porous host networks. Finally, the size-modulated MNPs were incorporated in poly(vinylidene fluoride) [PVDF]-based polytype nanogenerators as an electret filler to demonstrate their piezoelectric performance (VOC∼115.95 V and ISC∼1.04 μA), exhibiting substantial electromagnetic interference shielding.

Suvankar Mondal

Papers

Human motion interactive mechanical energy harvester based on all inorganic perovskite-PVDF

Dielectric and piezoelectric augmentation in self-poled magnetic Fe3O4/poly(vinylidene fluoride) composite nanogenerators

Size-modulation of functionalized Fe3O4: nanoscopic customization to devise resolute piezoelectric nanocomposites.

Cube shaped FAPbBr3 for piezoelectric energy harvesting devices

All-inorganic halide perovskite tuned robust mechanical-energy harvester: Self driven posture monitor and power source for portable electronics