A Comparative Study of BaTiO3/PDMS Composite Film and a PVDF Nanofiber Mat for Application to Flexible Pressure Sensors

Abstract

A Comparative Study of BaTiO3/PDMS Composite Film and a PVDF Nanofiber Mat for Application to Flexible Pressure SensorsIntensive research has been conducted to develop flexible piezoelectric pressure sensors, since selfpowering devices are advantageous for wearable electronic applications. Recently, two types of piezoelectric devices, ceramic-PDMS composite film and PVDF nanofiber mats, have drawn attention in the research community. Piezoelectric ceramics such as BaTiO3 (BTO) and PZT exhibit outstanding piezoelectric coefficients, while PDMS provides flexibility. In contrast, a PVDF nanofiber mat simultaneously exhibits piezoelectricity and flexibility. In the present study, a comparative analysis of BTO-PDMS composite film and a PVDF nanofiber mat for application to flexible pressure sensors was carried out. First, step-wise electric poling was conducted on these two types of pressure sensors, after which the open-circuit voltage (Voc) was measured under compressive force. The 1.8 V peak-to-peak Voc was measured in a BTO-PDMS composite with a 30 wt.% BTO content that was poled by 10 kV/mm electric field for 15 min. This peak-to-peak Voc of the BTO-PDMS composite increased further to ~ 4 V when it was poled for 24 hr. Unlike the BTO-PDMS composite films, the maximum Voc (1.1 V) was measured in a PVDF nanofiber mat that did not undergo subsequent electric poling. A BTO-PDMS composite film and a PVDF nanofiber mat were fabricated, and the compressive force and strain-rate dependencies of Voc and the short-circuit current (Isc) were investigated. Overall, the Voc and Isc of the BTO-PDMS composite film exceeded those of the PVDF nanofiber mat in a force range of 1 − 25 N and frequency range of 0.5 − 2.0 Hz. However, the Voc and Isc signals from the PVDF nanofiber mat were more stable than those from the BTO-PDMS composite film due to the longer lifetime of the signals.

Effective electromechanical properties and energy harvesting response in PMN-0.3PT/PDMS flexible piezoelectric composites: a combined experimental and theoretical study

“…Figures 7(a)-(d) show that there is an increase in the short circuit current density and open-circuit electric field with the increase in PMN-0.3PT content with increasing dynamic load and frequency. The maximum short circuit current density and open-circuit electric field generated under 50 N load at 5 Hz frequency for v r = 0.50 composite film is 34.66 nA cm −2 and 90 V cm −1 respectively, which is higher than reported in 1 vol.% CNT/30 vol.% PMN-0.3PT/PVDF [58], 40 vol.% BSST/PDMS [59], 30 wt.% BTO/PDMS [60]. In the present work, the frequency of excitation used is much less than the resonance frequency of the PMN-0.3PT ceramic.…”

Self-powered piezoelectric sensor based on BaTiO3/MWCNTs/PVDF electrospun nanofibers for wireless alarm system

“…On the contrary, piezoelectric polymer materials show excellent electromechanical response, available processibility, and highly flexible. Polyvinylidene fluoride polymer (PVDF), as an important piezoelectric polymer, owns several polymorph phases (such as α-phase, βphase, γ-phase, and δ-phase) [10][11][12]. The common and stable polymorph of PVDF is generally the α-phase PVDF.…”