Synergistic Optimization toward the Sensitivity and Linearity of Flexible Pressure Sensor via Double Conductive Layer and Porous Microdome Array

Abstract

Recently, wearable pressure sensors have attracted considerable interest in various fields such as healthcare monitoring, intelligent robots, etc. Although artificial structures or conductive materials have been well developed, the trade-off between sensitivity and linearity of pressure sensors is yet to be fully resolved by a traditional approach. Herein, from theoretical analysis to experimental design, we present the novel CPDMS/AgNWs double conductive layer (DCL) to synergistically optimize the sensitivity and linearity of piezoresistive pressure sensors. The facilely fabricated solid microdome array (SDA) is first employed as the elastomer to clarify the unrevealed working mechanism of DCL. Attributed to the synergistic effect of DCL, the DCL/SDA based sensor exhibits ultrahigh sensitivity (up to 3788.29 kPa–1) in an obviously broadened linearity range (0–6 kPa). We also demonstrated that the synergistic effect of DCL can be regulated with use of porous microdome array (PDA) to further optimize the sensing property. The linearity range can be improved up to 70 kPa while preserving the high sensitivity of 924.37 kPa–1 based on the interlocked PDA structure (IPDA), which is rarely reported in previous studies. The optimized sensitivity and linearity allow the competitive DCL/IPDA based sensor as a reliable platform to monitor kinds of physiological signals covering from low pressures (e.g., artery pulses), medium pressures (e.g., muscle expansions), to high pressures (e.g., body motions). We believe that the methodology along with the robust sensor can be of great potential for reliable healthcare monitoring and wearable electronic applications in the future.

Bio‐Inspired Hybrid Dielectric for Capacitive and Triboelectric Tactile Sensors with High Sensitivity and Ultrawide Linearity Range

“…The high sensitivity enables the precise recognition of tiny pressure variations with high signal‐to‐noise ratio. [ 10,11 ] The wide linearity range can preserve the high‐pressure resolution across a broad pressure spectrum and simplify the data processing and conversion. [ 12,13 ] Conventional capacitive tactile sensors with the solid dielectric sandwiched between electrodes suffer from the restricted sensitivity due to the low compressibility of the solid dielectric.…”

Natural bamboo leaves as dielectric layers for flexible capacitive pressure sensors with adjustable sensitivity and a broad detection range

“…For example, the dielectric layer is constructed by the template method to possess the porous structure, enhancing compressibility and further increasing the sensor sensitivity. [18][19][20][21][22][23][24][25] Furthermore, the fabrication of a regular or irregular microstructure of the elastomeric electrode or dielectric layer is also adopted to improve the sensitivity and the related performance of the sensor. 5,[26][27][28][29][30][31][32][33] Park et al combined the superiority of the two concepts, developing a capacitive sensor with a porous pyramid dielectric layer.…”

“…The assembled sensor showed a high sensitivity of 44.5 kPa À1 within the range of fewer than 100 Pa. 19 However, the construction of the porous structure or microstructure generally requires complicated and expensive approaches, such as photolithography, chemical etching, curing, and pre-stretching/UV exposure. 5,14,19,25,27,34,35 Therefore, a cost-effective and convenient process of producing the delicate microstructure is highly desired. Fortunately, some natural plants can facilitate the fabrication of the elaborate microstructure in the capacitive sensor to synergistically improve the sensing capability.…”

All-soft multiaxial force sensor based on liquid metal for electronic skin

“…On the other hand, the 3D dome structure can translate the tangential loading to change of cross-sectional area of LM microchannel along the dome. Unlike previous multiaxial force sensors with dome structure [22], the dome structure does not have to be rigid our proposed sensor. Previous multiaxial sensors used a rigid half-spherical structure to deliver external forces to the strain gauges or sensing structures beneath it by torque induced by the tangential force.…”