Muscle-Inspired Self-Healing Hydrogels for Strain and Temperature Sensor

Abstract

Recently, self-healing hydrogel bioelectronic devices have raised enormous interest for their tissue-like mechanical compliance, desirable biocompatibility, and tunable adhesiveness on bioartificial organs. However, the practical applications of these hydrogel-based sensors are generally limited by their poor fulfillment of stretchability and sensitivity, brittleness under subzero temperature, and single sensory function. Inspired by the fiber-reinforced microstructures and mechano-transduction systems of human muscles, a self-healing (90.8%), long-lasting thermal tolerant and dual-sensory hydrogel-based sensor is proposed, with high gauge factor (18.28) within broad strain range (268.9%), low limit of detection (5% strain), satisfactory thermosensation (−0.016 °C–1), and highly discernible temperature resolution (2.7 °C). Especially by introducing a glycerol/water binary solvent system, desirable subzero-temperature self-healing performance, high water-retaining, and durable adhesion feature can be achieved, resulting from the ice crystallization inhibition and highly dynamic bonding. On account of the advantageous mechanoreception and thermosensitive capacities, a flexible touch keyboard for signature identification and a “fever indicator” for human forehead’s temperature detection can be realized by this hydrogel bioelectronic device.

Highly Stretchable, Elastic, and Sensitive MXene-Based Hydrogel for Flexible Strain and Pressure Sensors

“…Comparing Young's modulus of the double-network hydrogels within 0-250% strain, it demonstrates that the addition of PVP significantly improves the stiffness of the hydrogels (Figure 2(b)). In terms of the hydrogel stretchability, the 3 wt% PVP hydrogel exhibits the maximum tensile fracture length of 2055%, which is superior to reported double-network hydrogels in some literatures [11,18,29]. When the PVP content is further increased, the tensile fracture length begins to decrease.…”

MXene hydrogels: fundamentals and applications

“…The excellent self-healing ability can be attributed to the dynamic crosslinking and supramolecular interactions between the various components of the organohydrogel. 53,54 As a result, 39 The 3D porous network of the aerogel has allowed for sensing a wider pressure range with higher sensitivity than that of MXene-rGO filtrated films. Besides, the strong interaction between MXene and rGO nanosheets has led to improved mechanical properties compared to pure rGO aerogels.…”

Progress in hydrogels for sensing applications: a review

“…Anyway, hydrogel-based temperature sensors are of clear interest because of their special and unique features. First of all, the possibility to tune the structure of the gels, coupled with their biocompatibility, made them suitable for a wide range of applications [28]. Moreover, even the output signal given by hydrogels can be tuned according to the desired behavior.…”