Bionic Fish-Scale Surface Structures Fabricated via Air/Water Interface for Flexible and Ultrasensitive Pressure Sensors

Abstract

In recent years, wearable and flexible sensors have attracted considerable research interest and effort owing to their broad application prospects in wearable devices, robotics, health monitoring, and so on. High-sensitivity and low-cost pressure sensors are the primary requirement in practical application. Herein, a convenient and low-cost process to fabricate a bionic fish-scale structure poly(dimethylsiloxane) (PDMS) film via air/water interfacial formation technique is presented. High-sensitivity flexible pressure sensors can be constructed by assembling conductive films of graphene nanosheets into a microstructured film. Thanks to the unique fish-scale structures of PDMS films, the prepared pressure sensor shows excellent performance with high sensitivity (-70.86% kPa). In addition, our pressure sensors can detect weak signals, such as wrist pulses, respiration, and voice vibrations. Moreover, the whole process of pressure sensor preparation is cost-effective, eco-friendly, and controllable. The results indicate that the prepared pressure sensor has a profitable and efficient advantage in future applications for monitoring human physiological signals and sensing subtle touch, which may broaden its potential applications in wearable devices.

3D Porous Superhydrophobic CNT/EVA Composites for Recoverable Shape Reconfiguration and Underwater Vibration Detection

“…The hydrophobicity of underwater sensors is an important parameter to guarantee the working stability and service life. However, the presented sensing devices, such as fiber optics, piezoelectric ceramics, and pressure‐sensitive electronics, were easily attacked by corrosive water for their hydrophilicity. Besides, they also confronted with challenges in materials flexibility, substrate attachment, and sensitivity preservation.…”

Transduction Mechanisms, Micro-Structuring Techniques, and Applications of Electronic Skin Pressure Sensors: A Review of Recent Advances

“…Regarding the research conducted to avoid photolithography techniques for micro-structuring, the group of Seimei Shiratori actually developed a peculiar technique in which uncured PDMS would be slowly dropped over water [ 143 ]. Due to differences in density and surface tension, the uncured PDMS would float on water, and after some time, form a thin cured film [ 143 ].…”

“…Regarding the research conducted to avoid photolithography techniques for micro-structuring, the group of Seimei Shiratori actually developed a peculiar technique in which uncured PDMS would be slowly dropped over water [ 143 ]. Due to differences in density and surface tension, the uncured PDMS would float on water, and after some time, form a thin cured film [ 143 ]. Possibly due to temperature differences between air and water during curing, and succeeding post-curing bending cycles, fish-scale like structures arose on the surface of the PDMS film, on the side that was in contact with air [ 143 ].…”

Self-encapsulation liquid metal materials for flexible and stretchable electrical conductors

“…8,9 In these applications, it is a general approach to fabricate a exible conductive composite by encapsulating electrical materials in a permeable polymer matrix, such as noble metal micro/nano particles, [10][11][12] carbon black, 13,14 and graphene/carbon nanotube materials. [15][16][17] These embedded materials, which are generally rigid and brittle, have difficulty in matching with each other and mismatch with the matrix because of stress concentration. Furthermore, with the development of additive manufacturing, different types of printing methods have emerged, which led to the result that the quest for insulative packaging is increasing.…”

“…Polydimethylsiloxane (PDMS) is widely used due to its chemical stability and low-cost preparation process, as well as exibility and transparency. 16 A exible package of PDMS lms with different surface microstructures has been used in stress sensing and 15,16 microuidics, 23,24 which has been prepared by means of moulding, spin coating, and injection. These processes, however, can cause damages to the lm and are oen expensive.…”