Zinc Oxide Nanowire-Poly(Methyl Methacrylate) Dielectric Layers for Polymer Capacitive Pressure Sensors

Abstract

Polymer capacitive pressure sensors based on a dielectric composite layer of zinc oxide nanowire and poly(methyl methacrylate) show pressure sensitivity in the range of 2.63 × 10(-3) to 9.95 × 10(-3) cm(2) gf(-1). This represents an increase of capacitance change by as much as a factor of 23 over pristine polymer devices. An ultralight load of only 10 mg (corresponding to an applied pressure of ∼0.01 gf cm(-2)) can be clearly recognized, demonstrating remarkable characteristics of these nanowire-polymer capacitive pressure sensors. In addition, optical transmittance of the dielectric composite layer is approximately 90% in the visible wavelength region. Their low processing temperature, transparency, and flexible dielectric film makes them a highly promising means for flexible touching and pressure-sensing applications.

An Omni‐Healable and Highly Sensitive Capacitive Pressure Sensor with Microarray Structure

“…The dielectric constant reached a very high point at low frequency when the content reached 2 wt %, which suggested the content of graphene exceeded the percolation value. Results indicated that the percolation threshold of graphene in the HPU solution was very low (<2 wt %) compared with other reported fillers . This is desirable for a flexible sensor because the dielectric constant can be improved without sacrificing the mechanical properties of the matrix.…”

“…Results indicated that the percolation threshold of graphene in the HPU solution was very low (< 2wt%)c ompared with other reported fillers. [49] This is desirable for af lexible sensorb ecause the dielectric constant can be improved without sacrificing the mechanical properties of the matrix.I nt his study,t he highest content of the graphene was 1.5 wt %, which was employed for subsequent sensor implementation.…”

Flexible and transparent capacitive pressure sensor with patterned microstructured composite rubber dielectric for wearable touch keyboard application

“…However, the inherent characteristics of a single dielectric limit the further development of capacitive pressure sensors. Therefore, to increase the sensing performance, some effective methods have been investigated, including doping fillers in insulating elastic dielectrics [16][17][18][19][20], introducing the ordered microstructures to the dielectric [14,[20][21][22][23][24], changing the internal microstructure of the dielectric [15,25], and so on. For example, Schwartz et al [26] reported a flexible capacitive pressure sensor embedded capacitive sensing element with a microstructured elastomer layer which revealed a fast response within a millisecond range and a great mechanical flexibility.…”

Enhanced Sensitivity of Iontronic Graphene Tactile Sensors Facilitated by Spreading of Ionic Liquid Pinned on Graphene Grid

“…When a larger ionic liquid droplet with 600 µm diameter is used, a capacitance change from 1 to 250 pF is observed under a pressure of 8 kPa (Figure S4 in the Supporting Information). In this case, the sensitivity is calculated to be 31.1 kPa −1 , which is one of the highest values reported in the medium‐pressure range (> a few kPa) so far (see Table S1 in the Supporting Information) . Although higher sensitivities have been reported in the previous reports, these values are typically obtained in extremely low pressure regimes (below 1 kPa) .…”