Fabrication of poly (vinylidene fluoride) films by ultrasonic spray coating; uniformity and piezoelectric properties

Sepide Taleb,Miguel A Badillo-Ávila,Mónica Acuautla

doi:10.1016/j.matdes.2021.110273

Sepide Taleb, Miguel A Badillo-Ávila + Show 1 more

Open Access

https://doi.org/10.1016/j.matdes.2021.110273

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Journal: Materials & Design	Publication Date: Nov 23, 2021
Citations: 9	License type: cc-by

Affiliation: University of Groningen

Abstract

Piezoelectric Poly (vinylidene fluoride) (PVDF) films with high flexibility are a suitable and promising replacement for rigid ceramic piezoelectric materials. However, for this purpose, enhancing piezoelectric properties and adopting an industrial fabrication method are of great importance. In this study, 5–9 µm thick PVDF films were fabricated by a nozzle-less ultrasonic spray coating (USC) system, followed by an annealing process at 100 °C. By applying proper spraying parameters, we could obtain highly uniform films with large d33 values (48 pm/V) and 56% crystallinity. Results show that the uniformity of the films plays an important role in the final piezoelectric properties. Thus, ultrasonic spray coating method can be used for fabrication of large-scale piezoelectric films with no need for poling or stretching processes.

Highlights

Since 1969, when PVDF was discovered as an organic piezoelectric material [1], a wide variety of research has been done on piezoelectric PVDF films
Ferroelectric PVDF-TrFE films have been recently used in nano electric devices such as nonvolatile memories [10], photodetectors [11], field-effect transistors [12], and PVDF composites are used for electric accessories and embedded capacitors [13]
We study the fabrication of freestanding PVDF films with enhanced piezoelectric properties via a nozzleless ultrasonic spray coating system without poling

Summary

Introduction

Since 1969, when PVDF was discovered as an organic piezoelectric material [1], a wide variety of research has been done on piezoelectric PVDF films. The outstanding mechanical properties of PVDF as a lead-free material, in comparison to inorganic piezoelectric single crystals and ceramics, have drawn the attention of many researchers [1,2,3,4]. Their focus has been mostly on polymer chain. Structure [5], fabrication methods [6,7], piezoelectric properties [2], mechanical strength [8], and sensor/actuator/energy harvesting applications [1,3,4,9]. Seeking a reliable and simple method for industrial fabrication of these piezoelectric films is of great importance

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