Highly sensitive ionic pressure sensor based on concave meniscus for electronic skin

Abstract

Flexible pressure sensing plays a critical role in the human–machine interaction; therefore highly sensitive pressure sensors have promising potential in such applications. Capacitive pressure sensors have inherent attributes of simple configuration and fast response time. However, the existing applications of sensors are limited by the limited sensitivity as well as complex manufacturing. Herein, a highly sensitive ionic pressure sensor with the microstructured dielectric layer has been proposed. The polycarbonate membrane is used as the template to manufacture the microstructure of the concave meniscus. By packing the top electrode, dielectric layer and bottom electrode, the ionic pressure sensor is fabricated. The sensor presents a sensitivity of 35.96 k Pa−1 with an excellent robustness of tolerating repeated pressure for at least 200 000 cycles without fatigue. In addition, the response time of the sensor is 21 ms and the limit of detection is 0.61 Pa. The ionic pressure sensor offers a highly sensitive sensing device for robotics and human–machine interaction. Furthermore, the concave meniscus realized by the template-based method provides a novel guideline for other microstructure-enabled devices.

Microengineering Pressure Sensor Active Layers for Improved Performance

“…To circumvent the often‐difficult processes required to fabricate molds, there has been increased interest in using readily available materials as molds, including commercially available or biological materials. [ 73,74,85,86 ] A commonly used commercial material is abrasive paper because it is cost‐effective, readily available, and can sometimes be used as a mold without the need for surfactant treatment. [ 86 ] In this process, the elastomer is simply dispersed on the paper, cured, and then demolded (Figure 4C).…”

“…An increasingly popular approach to improve the performance of capacitive pressure sensors is to manipulate the geometry of the pressure‐sensitive materials to enhance the compressibility of the dielectric layer. [ 15,67,71–74 ] When the dielectric layer is a bulk material, the applied pressure is converted to internal stress. By adding voids in the dielectric layer through microengineering, the layer can more readily deform with applied pressure, and consequently, can compress more easily ( Figure A,B).…”

First Decade of Interfacial Iontronic Sensing: From Droplet Sensors to Artificial Skins

“…[38] Utilizing the concave meniscus of pillar tip, Su et al reported an ionic pressure sensor with a high sensitivity S ≈ 10.04 kPa −1 at P < 2 kPa (Figure 10c). [225] Before loading, the electrode contacts only the periphery of the pillar. With the pressure increases, the contact area expands, leading to the formation of more EDL capacitors and increasing capacitance.…”

“…Copyright 2017, American Chemical Society. c) Reproduced with permission [225]. Copyright 2019, IOP Science.…”

Novel silicone-ionic liquid composite with keratin utilized as pressure sensor

“…Therefore, an ionic pressure sensor based on polymer composites with ILs, possessing both the elasticity of the polymer and the electrical conduction of the ILs, has received a lot of attention from researchers [25,[27][28] . For example, a highly sensitive ionic pressure sensor with a microstructured dielectric layer with a sensitivity of 35.96 kPa -1 has been prepared by Su et al [29] . Despite the great progress in ionic pressure sensors achieved so far, the development of ionic pressure sensor are stilled limited due to complicated fabrication processes and high cost.…”