Bio-based, self-adhesive, and self-healing ionogel with excellent mechanical properties for flexible strain sensor

Abstract

Bio-based ionogels with versatile properties are highly desired for practical applications.

Recent Progress in Bio‐Integrated Intelligent Sensing System

“…Recently, the needs for monitoring various sensing parameters, including blood pressure, compositions within body fluids, wound temperature, and limb movement, etc., propose many sensing requirements for the bioelectronics. [68][69][70][71][72] For these demands, sensors of BISS need to possess multiple sensing modalities, combining strain sensors, [73][74][75][76] temperature sensors,, [77][78][79] optical elements, [80][81][82][83][84] and other electrochemical types. [85][86][87] The integration of those functions is based on the fact that the ideal sensitive unit in one channel can precisely reflect one specific change of its surrounding environment (sensitivity) without the interference of other modalities (specificity).…”

Highly Conductive, Transparent, Adhesive, and Self‐Healable Ionogel Based on a Deep Eutectic Solvent with Widely Adjustable Mechanical Strength

“…Remarkably, the PEI/PAA/CMC ionogels containing >70 wt% CCl-U presented an ultra-wide range of mechanical properties by simply changing the PEI/PAA mass ratio, which surpassed most of the recently reported ionogels (Figure 3e). [3,5,22,26,33,[45][46][47][48] Note that all ionogels contained at least 50% ILs to achieve a fair comparison.…”

“…The ionogels with such high healed stress and strain outperform most of the previously reported self-healable ionogels (Figure 4c and Table S3, Supporting Information). [20][21][22][48][49][50][51][52] Additionally, given that these reversible physical interactions (sacrificial bonds) can be readily reformed after being disrupted during stretching, the strong electrostatic interactions and hydrogen bonds are considered to be beneficial for fatigue resistance and self-recovery of the PEI/PAA/CMC ionogels. The excellent fatigue resistance of the PEI 0.06 /PAA 0.25 /CMC 0.01 ionogel was confirmed by 10 continuous tensile and compression cycling curves without any residence time (Figure S10, Supporting Information).…”

A facile strategy for fabricating self-healable, adhesive and highly sensitive flexible ionogel-based sensors

“…The adhesion strength of PEI 3.9 /PAA 9 / DES 72 to glass reached up to 0.35 MPa, which was higher than that of most reported works. 7,25,[41][42][43] More importantly, the PEI 3.9 /PAA 9 /DES 72 ionogel with excellent adhesiveness and biocompatibility could tightly adhere to the finger or leg joints and the bonding area can withstand multiple bending cycles (Videos S1 and S2, ESI †). Besides, it can be observed that the large deformation of the ionogel sheet brought about a distinct stripping lag when being peeled off from human skin, and there were no residual ionogel or DES after detachment from the skin.…”

“…22,23 For this reason, most of the previously reported ionogel-based sensors suffered from limited sensing range and sensitivity. 15,24,25 In addition, strain sensors are inevitably scratched or damaged under complex deformation, such as bending, squeezing and twisting. 26 Persistent damage will ultimately result in premature failure or even safety problems.…”