Microstructured Porous Capacitive Bio-pressure Sensor Using Droplet-based Microfluidics

Abstract

Abstract
Background: Devices that mimic the functions of human skin are known as “electronic skin,” and
they must have characteristics like high sensitivity, a wide dynamic range, high spatial homogeneity,
cheap cost, wide area easy processing, and the ability to distinguish between diverse external inputs.
Methods: This study introduces a novel approach, termed microfluidic droplet-based emulsion selfassembly (DMESA), for fabricating 3D microstructured elastomer layers using polydimethylsiloxane
(PDMS). The method aims to produce accurate capacitive pressure sensors suitable for electronic skin
(e-skin) applications. The DMESA method facilitates the creation of uniform-sized spherical micropores
dispersed across a significant area without requiring a template, ensuring excellent spatial homogeneity.
Results: Micropore size adjustment, ranging from 100 to 600 ?m, allows for customization of pressure
sensor sensitivity. The active layer of the capacitive pressure sensor is formed by the three-dimensional
elastomer itself. Experimental results demonstrate the outstanding performance of the DMESA
approach. It offers simplicity in processing, the ability to adjust performance parameters, excellent
spatial homogeneity, and the capability to differentiate varied inputs. Capacitive pressure sensors
fabricated using this method exhibit high sensitivity and dynamic amplitude, making them promising
candidates for various e-skin applications. Conclusion: The DMESA method presents a highly
promising solution for fabricating 3D microstructured elastomer layers for capacitive pressure sensors
in e-skin technology. Its simplicity, performance adjustability, spatial homogeneity, and sensitivity to
different inputs make it suitable for a wide range of electronic skin applications.