Development of In-Situ Poled Nanofiber Based Flexible Piezoelectric Nanogenerators for Self-Powered Motion Monitoring

Minjung Kim,Afeesh Rajan Unnithan,Cheol Sang Kim,Chan Hee Park,Vignesh Krishnamoorthi Kaliannagounder,Arathyram Ramachandra Kurup Sasikala

doi:10.3390/app10103493

Minjung Kim, Afeesh Rajan Unnithan + Show 4 more

Open Access

https://doi.org/10.3390/app10103493

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Abstract

Energy harvesting technologies have found significant importance over the past decades due to the increasing demand of energy and self-powered design of electronic and implantable devices. Herein, we demonstrate the design and application of in situ poled highly flexible piezoelectric poly vinylidene fluoride (PVDF) graphene oxide (GO) hybrid nanofibers in aligned mode for multifaceted applications from locomotion sensors to self-powered motion monitoring. Here we exploited the simplest and most versatile method, called electrospinning, to fabricate the in situ poled nanofibers by transforming non-polar α-phase of PVDF to polar β- phase structures for enhanced piezoelectricity under high bias voltage. The flexible piezoelectric device fabricated using the aligned mode generates an improved output voltage of 2.1 V at a uniform force of 12 N. The effective piezoelectric transduction exhibited by the proposed system was tested for its multiple efficacies as a locomotion detector, bio-e-skin, smart chairs and so on.

Highlights

Energy harvesting technologies have found significant importance over the past decades due to the increasing demand of energy and self-powered design of electronic and implantable devices [1,2,3].The concept of self-powered smart electronics such as wearable devices for personal health care [4], biomonitoring [5] and environmental monitoring [6] necessitates unique, cost effective and sustainable energy storage systems [7]
The relative proportion of the β phase formation was assessed from X-ray powder diffraction (XRD) by calculating the ratio of the peak intensity for β (Iβ ) and sum of peak intensities of α (Iα ) and β, respectively, as given below [37]
In order to enhance the piezoelectric β phase nucleation, graphene oxide (GO) was selected as a filler due to its active interaction with the poly vinylidene fluoride (PVDF) matrix as well as its higher dielectric constant

Summary

Introduction

Energy harvesting technologies have found significant importance over the past decades due to the increasing demand of energy and self-powered design of electronic and implantable devices [1,2,3]. PVDF is an inexpensive, highly nonreactive and a flexible polymer [25] with four crystalline phases, namely α, β, γ and δ, based on the chain formation [26,27,28] Among these phases, α is non-polar and does not show any piezoelectricity. In order to enhance the piezoelectricity, the β and γ phases can be generated by nanoparticle doping [29], 2D metal dichalcogenides [7], electrospinning process [30] etc In this regard, graphene oxide (GO) has shown extensive applicability due to its superior property to induce the nucleation of β and γ phases by the electrostatic interaction and/or hydrogen bonding between the oxygen functionalities of GO and PVDF as well as its superior mechanical, thermal and electrical properties [31]. The effective piezoelectric transduction exhibited by the proposed system enables its multiple efficacies as a locomotion detector, bio-e-skin, smart chairs and so on

Piezoelectric Nanofiber Fabrication

Characterisation

Results and Discussion

Conclusions