Wearable Core-Shell Piezoelectric Nanofiber Yarns for Body Movement Energy Harvesting

Abstract

In an effort to fabricate a wearable piezoelectric energy harvester based on core-shell piezoelectric yarns with external electrodes, flexible piezoelectric nanofibers of BNT-ST (0.78Bi0.5Na0.5TiO3-0.22SrTiO3) and polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) were initially electrospun. Subsequently, core-shell piezoelectric nanofiber yarns were prepared by twining the yarns around a conductive thread. To create the outer electrode layers, the core-shell piezoelectric nanofiber yarns were braided with conductive thread. Core-shell piezoelectric nanofiber yarns with external electrodes were then directly stitched onto the fabric. In bending tests, the output voltages were investigated according to the total length, effective area, and stitching interval of the piezoelectric yarns. Stitching patterns of the piezoelectric yarns on the fabric were optimized based on these results. The output voltages of the stitched piezoelectric yarns on the fabric were improved with an increase in the pressure, and the output voltage characteristics were investigated according to various body movements of bending and pressing conditions.

Composites, Fabrication and Application of Polyvinylidene Fluoride for Flexible Electromechanical Devices: A Review

“…In 2020, Mokhtari et al [143] fabricated a high-performance hybrid piezofiber composed of a PVDF and barium titanate (BT) nanoparticle (mass ratio 10:1). These fibers are knitted to fabricate a wearable energy generator with a power density of 87 µW cm -3 and a maximum voltage output of 4 V. In 2019, Sang et al [144] prepared a wearable piezoelectric energy harvester based on core-shell piezoelectric yarns prepared by twining the yarns around a conductive thread. The yarns were composed of flexible piezoelectric nanofibers of BNT-ST and PVDF-TrFE by electrospinning.…”

“…This confirmed that it was possible to fabricate low-cost and lightweight electronic devices with reduced quantities of metal oxides and pressure sensing devices. between temperature and recovery time [94]; (e) Generated output voltages, output currents, output powers by Finger bending, knee and elbow movements [144]; (f) Pressure sensor embedded in the bottom of the insole or stuck on human arm and voltage generated by jumping, walking, running and different bending angles' elbows [123].…”

“…Sang et al [144] manufactured a wearable piezoelectric energy harvester by electrospinning PVDF-TrFE and BNT-ST(0.78Bi0.5Na0.5TiO3-0.22SrTiO3). The generated output voltages, output currents, output powers by finger bending, and knee and elbow movements are shown in Figure 11e.…”

Recent Research Trends of Flexible Piezoelectric Nanofibers for Energy Conversion Materials

“…Energy harvesting properties according to bending (b) elbow and (c) knee movements as the guard stitched in the elbow and knee parts, respectively. (d) Energy harvesting properties according to clapping movements as a cotton glove stitched in the effective area, and (e) energy harvesting properties according to walking and running movements as a shoe insole stitched in the effective area 28) .…”

Neoteric Conjugative Electrospinning towards Alloplastic Nanofiber Yarns Affording Enhanced Upconversion Luminescence and Tailored Magnetism

“…As a raw material, one‐dimensional nanofibers are widely used for designing and constructing products with two‐dimensional and three‐dimensional structures . These downstream products have unique optical, mechanical, electrical, magnetic and biological properties, which are widely used in the photocatalyst materials, biological textiles, electronic devices, gas‐sensitive materials and other fields. In recent years, the commonly used electrospinning templates are polyvinyl pyrrolidone (PVP), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), etc.…”