One of the key challenges in developing gel‐based electronics is to achieve a robust sensing performance, by overcoming the intrinsic weaknesses such as unwanted swelling induced deformation, signal distortion caused by dehydration, and large hysteresis in sensing signal. In this work, a structural gel composite (SGC) approach is presented by encapsulating the conductive hydrogel/MXene with a lipid gel (Lipogel) layer through an in situ polymerization. The hydrophobic Lipogel coating fulfills the SGC with a unique anti‐swelling property at an aqueous environment and excellent dehydration feature at an open‐air, thus leading to long‐term ultra‐stability (over 90 days) and durability (over 2000 testing cycles) for underwater mechanosensing applications. As a result, the SGC based mechanoreceptor demonstrates high and stable sensitivity (GF of 14.5). Moreover, several SGC based conceptual sensors with high sensitivity are developed to unveil their profound potential in underwater monitoring of human motions, waterproof anti‐counterfeiting application, and tactile trajectory tracking.

Hydrogel electronics have attracted growing interest for emerging applications in personal healthcare management, human‐machine interaction, etc. Herein, a “doping then gelling” strategy to synthesize supramolecular PANI/PAA hydrogel with a specific strand entangled network is proposed, by doping the PANI with acrylic acid (AA) monomers to avoid PANI aggregation. The high‐density electrostatic interaction between PAA and PANI chains serves as a dynamic bond to initiate the strand entanglement, enabling PAA/PANI hydrogel with ultra‐stretchability (2830%), high breaking strength (120 kPa), and rapid self‐healing properties. Moreover, the PAA/PANI hydrogel‐based sensor with a high strain sensitivity (gauge factor = 12.63), a rapid responding time (222 ms), and a robust conductivity‐based sensing behavior under cyclic stretching is developed. A set of strain sensing applications to precisely monitor human movements is also demonstrated, indicating a promising application prospect as wearable devices.

Hydrogels have been attracting increasing attention in wearable electronics, due to their intrinsic biomimetic features, highly tunable chemical-physical properties (mechanical, electrical, etc), and excellent biocompatibility. Among many proposed varieties, conductive...

A seamless and tough interface to integrate incompatible/immiscible soft materials is highly desired for flexible/wearable electronics and many soft devices with multi-layer structures. Here, a surfactant-mediated interfacial chemistry is introduced to achieve seamless and tough interfaces in soft multi-layer structures, with an ultra-high interfacial toughness up to ≈1300 J m −2 for the architectural gel hybrid (AGH). The reversible noncovalent interfacial interactions efficiently dissipate energy at the interface, thereby providing excellent durability. The interfacial toughness only decreases by ≈6.9% after 10 000 tensile cycles. This strategy can be universally applied to hybrid systems with various interfaces between an interior hydrogel (PAA, PVA, PAAm, and gelatin) and an exterior hydrophobic soft matter (ionogel, lipogel and elastomer). The AGH-based mechano-sensor presents high robustness and stability in a wide range of conditions, including open air, underwater, and various solvents and temperatures. Epidermal bio-monitoring, tactile trajectory, and facial expression recognition are demonstrated using the AGH sensors in various environments. A rich set of electrophysiological signals of high quality are acquired.

Hydrogel-based wearable sensors have flourished as encouraging candidates for human mechanosensation due to their controllable conductivity and tailorable mechanical performances. However, it is still a great challenge to fabricate hydrogelbased wearable sensors with long-term durability and long service lifespan, while maintaining good sensing sensitivity and mechanical performances. This work demonstrates the formulation of a novel urushiol-induced hydrogel of exclusive microstructure and long-term durability by facile one-step copolymerization, and the development of hydrogel-based mechanosensors with brilliant durability, long lifespan, and long-term and robust adhesiveness in air and water. The hydrogel-based sensors possess extraordinary self-recovery capability and eminent synchronism between applied strains and output signals, which can contribute to the synergistic effect of the fast mobility of flexible polymer chains assigned by the flexible alkyl chains and the construction of an optimized energy dissipation mechanism endowed with molecular-scale dynamic interactions. Moreover, the obtained hydrogel-based sensors can detect mechanical strains and distinguish human motions with high sensitivity, stable electrical signal responsiveness, and good biocompatibility, and have potential applications as wearable sensors for human motion monitoring.

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