Highly Sensitive Flexible Pressure Sensor Based on Silver Nanowires-Embedded Polydimethylsiloxane Electrode with Microarray Structure

Abstract

Flexible pressure sensors have attracted increasing research interest because of their potential applications for wearable sensing devices. Herein, a highly sensitive flexible pressure sensor is exhibited based on the elastomeric electrodes and a microarray architecture. Polydimethylsiloxane (PDMS) substrate, coated with silver nanowires (AgNWs), is used as the top electrode, while polyvinylidene fluoride (PVDF) as the dielectric layer. Several transfer processes are applied on seeking facile strategy for the preparation of the bottom electrode via embedding AgNWs into the PDMS film of microarray structure. The flexible pressure sensor integrates the top electrode, dielectric layer, and microarray electrode in a sandwich structure. It is demonstrated that such sensors possess the superiorities of high sensitivity (2.94 kPa), low detection limit (<3 Pa), short response time (<50 ms), excellent flexibility, and long-term cycle stability. This simple process for preparing such sensors can also be easily scaled up to construct pressure sensor arrays for detecting the intensity and distribution of the loaded pressure. In addition, this flexible pressure sensor exhibits good performance even in a noncontact way, such as detecting voice vibrations and air flow. Due to its superior performance, this designed flexible pressure sensor demonstrates promising potential in the application of electronic skins, as well as wearable healthcare monitors.

Fabrication of capacitive yarn torsion sensors based on an electrospinning coating method

“…Generally, capacitive sensors are composed of two electrodes, between which is a dielectric material. It is known that the capacitance is affected by the dielectric constant of the material, the area of the interface between material and electrode and the distance between the two electrodes . One easy way to improve the sensitivity of the capacitive response is to increase the change in the distance induced by an external stimulus, such as compressive force.…”

“…Capacitive sensors offer numerous advantages in terms of their capability to provide selectivity and higher sensitivity compared to resistive sensors that inherently require higher electric conductivity . The basic structure of capacitive sensors comprises a dielectric material and two electrodes at top and bottom, which sensitively respond to external stimuli based on the dielectric constant, the distance between the two electrodes and the area of the interfaces between dielectric material and electrode . This basic structure has been modified in different forms to develop next‐generation devices.…”

Untethered soft robotics

“…Silver nanowires are particularly useful as fillers given their high electrical conductivity, and can be incorporated into elastomers to form stretchable electrodes [89][90][91] or even LEDs 89 . Graphene sheets and graphene nanoscrolls are also effective for enabling conductivity in elastomers under high strain 92 .…”

“…Capacitive pressure sensors can also be created by deforming a dielectric layer between electrodes constructed from these materials 90,93 . Recent work has incorporated microstructures into such electrodes to increase deformation at low pressures and dramatically improve sensitivity, yielding easy-to-fabricate, highly sensitive, wearable pressure sensors capable of measuring vocal vibration and air flow 90 .…”

“…Recent work has incorporated microstructures into such electrodes to increase deformation at low pressures and dramatically improve sensitivity, yielding easy-to-fabricate, highly sensitive, wearable pressure sensors capable of measuring vocal vibration and air flow 90 .…”