▎ 摘　　要

NOVELTY - Flexible energy harvester, comprises piezoelectric nanogenerator comprising a middle layer of barium calcium titanate (BCT)-barium zirconate titanate (BZT)-reduced graphene oxide (rGO)-poly(vinylidene fluoride-co-hexafluoropropylene) P(VDF-HFP) nanofiber sheet, where the middle layer of nanofiber membrane is sandwiched between two nickel-copper polyester fabric. USE - The harvester is useful for scavenging mechanical energy efficaciously (claimed) and in wearable device for wrist, or knee, and wearable or portable electronic devices e.g. smart watches, fitness trackers, mobile phones and calculators. ADVANTAGE - The harvester: utilizes piezoelectric nanogenerators prepared via nanofibers which are cost-effective, eco-friendly and flexible for wearable and portable electronic devices; and is lightweight, flexible, and ecologically innocuous nanofiber mat. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing BCT-BZT-rGO-P(VDF-HFP) nanofiber membrane, comprising (a) dispersing P(VDF-HFP) with solvent N,N-dimethylformamide or acetone to prepare sol A, (b) mixing BCT-BZT-rGO nanoparticles separately with N,N-dimethylformamide or acetone and stirring the mixture for 1 hour with the help of magnetic stirrer to prepare sol B, (c) mixing sol A and sol B with constant stirring at 50 degrees C for 24 hours until the desired viscosity is achieved, (d) filling the solution of the preceding step into a plastic syringe, (e) feeding the solution into a spinneret that has been clipped with the positive terminal of the high voltage power supply, and other end of spinneret is clipped to an aluminum foil placed on the collector plate, (f) adjusting the distance between the collector and the tip of the spinneret at 15 cm and applied voltage at 16kV, (g) forming of extremely fine continuous nanofibers, (h) collecting many threads onto the aluminum foil placed on the collector plate and (i) peeling off nanofiber membrane from the aluminum foil.