Dependence of the Impact Response of Polyvinylidene Fluoride Sensors on Their Supporting Materials’ Elasticity

Abstract

Polyvinylidene fluoride (PVDF) is popular sensing material because of its unique piezoelectric characteristics. In this work an impact sensor was prepared from a sandwiched structure PVDF film, and the related detection circuits were presented. The dependence of the PVDF sensors' response on the elasticity of the supporting materials was examined and discussed. Here two response indexes were discussed, which were the peak-to-peak voltage (Vpp) and the recovery time. Firstly, falling impact experiments were executed on desk-supported PVDF sensors (100 μm PVDF film) using free falls of different weights from different heights. Then the same shock experiments were repeated on the same sensor, but changing the backstops to a sponge and rubber, respectively. On the desk, the values of Vpp were bigger than when the other two backstops were used; but the changes of the impact energy could not be reflected by the PVDF sensor when it was supported by a hard material. It was found that the biggest sensitivity of the voltage response (about 96.62 V/J) was obtained by the sponge-supported sensor; for the same sensor, when it was supported by rubber, the slope was 82.26 V/J. Moreover, the recovery time for the desk-supported sensor was almost constant, varying from 0.15 to 0.18 s, while for the same sensor supported by sponge or rubber, its recovery time changed with the shifting of the impact energy in the range of 0.02∼0.36 s, but no pattern could be found in the recovery-time characteristics.

Using Annealing Treatment on Fabrication Ionic Liquid-Based PVDF Films

“…Then, the film was cooled down to 35 • C for 30 min, and then left at room temperature. Secondly, the film was immersed in a water bath to remove excessive solvent IL at various temperatures (25,40,50,60, and 70 • C) for 2 h, and then removed moisture by air dry. Without operating the above second step, i.e., PDI composite film without immersion in hot water for annealing treatment (AT), named with the abbreviation PDI no_AT, was prepared for the purpose of comparison.…”

Flexible Pressure Sensors Based on Screen-Printed P(VDF-TrFE) and P(VDF-TrFE)/MWCNTs

“…They also exhibit stable piezo, pyro and ferroelectric properties. Other attractive features of P(VDF-TrFE) are good pressure sensitivity, wide frequency response, cost effectiveness, ease of fabrication and light weight [25][26][27][28]. Fig.…”

Screen printed flexible pressure sensors skin

“…Polyvinylidene fluoride (PVDF) and its copolymer Trifluoroethylene (TrFE) films have been widely investigated due to their mechanical flexibility and stable piezo, pyro and ferroelectric properties. Attractive features of PVDF-TrFE based films are high sensitivity, wide frequency response, flexibility, cost effectiveness, ease of fabrication and light weight [11][12][13][14].…”