Nanofiber alignment tuning: An engineering design tool in fabricating wearable power harvesting devices

Abstract

Piezoelectrics are one of the most important materials used for harvesting energies. Several piezoelectric nanostructures have been used to construct nanogenerators (NGs). Nanofibers made by piezo-polymers, especially polyvinylidene fluoride (PVDF) because of their high flexibility, biocompatibility, and low cost, have shown wonderful growth as the key materials for NGs. Despite these favorable properties, fabricated nanofibrous devices still has low efficiency and many studies have been conducted to characterize and improve the performance of the PVDF nanofibers. Here we tried to fabricate PVDF NG device based on align nanofibers to improve the NGs output, using two different methods rotary collector and applying magnetic field. Characteristics of these structures are evaluated utilizing X-ray diffraction, Fourier transform infrared, differential scanning calorimetry, and scanning electron microscopy. Electrical response of fabricated samples is measured through utilization of an impedance analyzer at room temperature. Results demonstrate that crystalline structure increases in both methods but sample fabricated by rotary collector in magnetic field has more improvement in their outputs. This result shows that in addition to the crystalline structure, nanofibers alignment and arrangement play important roles in piezoelectric properties of sample, as well as NG efficiency. These results teach us to establish engineering design rules for wearable power harvesting devices.

Biomechanical and Acoustic Energy Harvesting from TiO2 Nanoparticle Modulated PVDF Nanofiber Made High Performance Nanogenerator

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An Effective Wind Energy Harvester of Paper Ash-Mediated Rapidly Synthesized ZnO Nanoparticle-Interfaced Electrospun PVDF Fiber

“…Thus, induction of an electroactive β phase that is the most desirable phase for mechanical energy harvesting becomes a challenging task. , Among different techniques (i.e., stretching, heat treatment, electrical poling, etc. ), electrospining has recently become the most fascinating technique as it is a one-step method for β-phase induction in PVDF fiber via in situ mechanical stretching and electrical poling during fiber formation. , Thus, a recent literature survey showed that the electrospun PVDF nanofibers are extensively being utilized in energy conversion, , wearable power generation, , and various types of sensors. , However, in most of the cases, PVDF electrospun fibers still showed the coexistence of a nonpolar α phase with the induced polar β phase, and thus, researchers focused on the doping of different types of inorganic nanofillers (i.e., MWCNTs, ZnO, MoS 2 , BaTiO 3 , and Fe 3 O 4 ) to improve the β-phase content of PVDF fiber. − However, the synthesis of such inorganic fillers needs a multistep fabrication procedure and thus is time-consuming. In this context, quick fabrication of the filler by a cost-effective approach is beneficial for the overall functionality of the PVDF-based energy generation system.…”

Design and fabrication of a piezoelectric out-put evaluation system for sensitivity measurements of fibrous sensors and actuators

“…Ultrasonic stirring was used to form a uniform solution. Nanocomposite fibrous mats were fabricated by horizontal electrospinning (FNM© electrospinning system - Iran) according to previous studies (Table 1) [30,35].…”