Flexible and Highly Sensitive Pressure Sensor Based on Microdome-Patterned PDMS Forming with Assistance of Colloid Self-Assembly and Replica Technique for Wearable Electronics

Abstract

Flexible pressure sensors are one of the vital component units in the next generation of wearable electronics for monitoring human physiological signals. In order to improve the sensing properties of the sensors, we demonstrate flexible, tunably resistive pressure sensors based on elastic microstructured polydimethylsiloxane (PDMS) film via a simple, low-cost colloid self-assembly technology, which uses monodispersed polystyrene (PS) microspheres as monolayer and an ordered sacrificial template. The sensors exhibit high sensitivity of -15 kPa under low pressure (<100 Pa), with fast response time (<100 ms), high stability over 1000 cycles of pressure loading/unloading, low-pressure detection limit of 4 Pa, and wide working pressure regime (<5 kPa) by optimizing the size of PS microspheres. Moreover, the multipixel arrays of the pressure sensor are fabricated to illustrate the sensing ability of space pressure distribution. The developed flexible pressure sensors are successfully used to detect human neck pulse, show great promise for monitoring human body motions, and have potential applications in wearable devices.

Silver Telluride Nanowire Assembly for High‐Performance Flexible Thermoelectric Film and Its Application in Self‐Powered Temperature Sensor

“…Figure 6a displays the schematic representation of the thermoelectric self-powered temperature sensor, which consists of Ag 2 Te nanowire film, silver paste, and external circuit (copper wires) equipped with voltmeter. [26] We also note that the response time is longer than the other sensors, such as pressure sensors [27] and some temperature sensor. The finger temperature and environmental temperature were about 36.5 and 25.0°C, respectively.…”

Self‐Assembly of Colloidal Spheres toward Fabrication of Hierarchical and Periodic Nanostructures for Technological Applications

“…Due to the features of simplicity, cost‐effectiveness and well‐controlled morphology, the self‐assembly of colloidal spheres has been extensively applied to fabricate hierarchical and periodic 2D or 3D nanostructures, and subsequently applied in many technological fields such as the sensors and surface‐enhanced Raman scattering (SERS) . Figure A shows the fabrication process of a flexible pressure sensor based on self‐assembly of colloid PS microspheres and PDMS–PDMS pattern transfer technology.…”

“…The inset shows the resistance change curves of the sensor extracted from the red part. Reproduced with permission . Copyright 2017, American Chemical Society.…”

P‐138: A High Sensitive Resistive Pressure Sensor with NH4HCO3‐induced Porous Structure Active Layer

“…To improve the sensitivity, two methods are generally utilized. One is to fabricate pattern arrays on the substrate such as inverted pyramids [5] and micro dome [16], the other is to induce pores in the PSR-layer [17,18]. Yet previous studies show diverse materials and complex fabrication processes.…”

“…Yet previous studies show diverse materials and complex fabrication processes. And for most sensors, the resistance decreases as the pressure increases resulting in slight changes in resistance and requirements of amplifiers under high pressure [16][17][18][19][20].…”