Kunlin Chen

In flexible sensing applications, the long-term reliability of hydrogels is challenged by sustained and cyclic mechanical deformations. Exposure to forces such as bending and stretching ultimately diminishes sensing fidelity and accelerates material fatigue, shortening the functional lifetime. To improve hydrogel durability and minimize hysteresis, this study develops a composite hydrogel composed of a copolymer matrix of 3-methacrylamidophenylboronic acid and acrylamide integrated with polydopamine-modified sericin and aluminum ions. Leveraging a synergy of three dynamic bonds (boronic ester, hydrogen, and metal coordination bonds), the hydrogel demonstrates outstanding self-healing, achieving 88% recovery in just 20 min. It also exhibits excellent mechanical characteristics, such as an elongation at break of 390% and a tensile strength of 31 kPa, along with a low hysteresis of 3.7% at 100% strain. Furthermore, the hydrogel exhibits stable electrical conductivity, high strain sensitivity, and low hysteresis. When used as a wearable sensor, it effectively provides real-time monitoring of human joint movements, maintaining a stable signal output even under prolonged and repeated deformation. These properties indicate significant potential for implementation in flexible sensing systems and rehabilitation training protocols.

Advancing the development of sensitive, rapid-response fabric humidity sensors and textiles with active thermal management is crucial for enhancing wearer safety and user experience in complex environments. Herein, a double-shell microcapsule featuring a rough surface was developed by growing a zinc oxide shell on silica microcapsules. A polyacrylate containing acetoacetate groups was crosslinked with carboxymethyl chitosan, resulting in a stable composite system. This system was further stabilized through electrostatic interactions with MXene nanosheets. The microcapsules were subsequently integrated into a conductive composite coating applied to fabric through a finishing process. Based on effective encapsulation of the phase-change core material, the microcapsules exhibited a phase-change enthalpy of 57.33 J/g, demonstrating excellent thermal energy storage capacity. Due to the hydrophilicity of the protonated amino groups in carboxymethyl chitosan and the active sites on the rough microcapsule surface, the composite coating exhibited a remarkable humidity sensitivity of 10186%. Regarding antibacterial performance, the protonated amino groups in carboxymethyl chitosan synergize with the zinc oxide-containing shell, achieving inhibition rates of 99.78% and 99.99% against E. coli and S. aureus, respectively, demonstrating excellent broad-spectrum antibacterial activity. When applied for perspiration monitoring on human arm, it demonstrated real-time humidity tracking and effective thermal management capabilities, showcasing its promising applications in smart wearable technology.

Conductive hydrogels often suffer from structural damage, fatigue, and signal drift under repeated deformation, limiting their long‐term performance in flexible sensing. To overcome these challenges, this study developed a sericin‐MXene/phenylboronic acid‐polyacrylamide (PADS‐MXene) composite hydrogel by copolymerizing 3‐acrylamidophenylboronic acid with acrylamide and incorporating polydopamine‐modified sericin‐functionalized MXene. In this system, the polydopamine‐modified sericin (PDA‐SS) not only expanded the interlayer spacing of MXene and prevented nanosheet aggregation but also introduced polar functional groups, strengthening hydrogen bonding between MXene and the polyacrylamide network. The resulting hydrogel exhibits excellent mechanical properties, with a fracture strength of 60 kPa and a fracture strain of 380%, coupled with low hysteresis (1.65% after 30 cycles), and efficient self‐healing ability. MXene also enhances its high electrical conductivity and photothermal response, enabling rapid 20°C within 300 s under near‐infrared light. Functioning as a wearable strain sensor, the hydrogel can reliably monitor movements across various parts of the human body and maintain stable performance even after 2000 cycles at 50% strain. It also enables handwriting posture correction via pressure distribution and Morse code messaging via short/long presses for emergency communication. These features highlight its potential for durable, multifunctional flexible sensing systems.

Rising demand for textiles combining odor control, antibacterial properties, and ultraviolet (UV) protection has stimulated interest in durable functional finishing approaches. Microcapsules were prepared using 5‐propylhydantoin (PHDT) and menthol essential oil as dual cores, encapsulated within a polyurethane shell incorporating 2‐(4‐bromophenyl)‐5‐phenylthiophene‐modified β‐cyclodextrin (β‐CD). The microcapsules were further applied to fabric, and the adsorption and degradation behaviors toward trans‐2‐nonenal were investigated. The dual‐core system, together with the photocatalytic activity of the modified β‐CD, significantly improved odor removal efficiency. Further analysis of the individual and combined contributions of PHDT and the thiophene‐based component revealed a pronounced synergistic effect, leading to improved adsorption and degradation performance on the treated fabrics. In addition, the functional cotton fabric exhibited strong antibacterial activity, achieving inhibition efficiencies of 97% against Escherichia coli and 92% against Staphylococcus aureus . The integration of modified β‐CD also substantially improved UV protection, increasing the ultraviolet protection factor (UPF) to 71, while maintaining a value of approximately 40 after 30 abrasion cycles. This study presents a feasible pathway for developing multifunctional textile materials with durable odor management and protective performance.

Hydrogels offer considerable promise as flexible sensors.