Enke Feng,Xiaoqin Li,Zhongquan Yu,Zhiming Yang,Zhiqiang Wu,Mengzhen Zhang,Qin Wang,Xinxian Ma
Hydrogel-based flexible electronics have received increasing attention owing to the requirement in a variety of applications. However, the design and development of underwater and self-adaptive high-temperature strain sensors remain a significant challenge because of the swelling and dehydration of hydrogels in aquatic environments and extreme climate conditions. Herein, a versatile gel with superior self-adhesiveness, long-lasting underwater stability, excellent high-temperature tolerance and long-term non-drying properties is successfully prepared, which can serve as a wearable sensor for precisely and reliably detecting diverse body movements and the direction of human movements in air and aquatic environments. Meanwhile, based on the Morse code expression, the as-fabricated gel sensor can also be utilized as a wearable communication device for delivering various messages to the receiver. Furthermore, a wireless sensor with high-temperature adaptability is constructed, which can transmit in real time the motion signals at high temperature to the specific APP of a smartphone at room temperature via wireless communication. This strategy provides a new perspective and great convenience for motion monitoring under harsh conditions. In particular, the as-prepared gel demonstrates an obvious transparency-shifting behavior in different polar solvents, thus inspiring us to engineer it as a novel water-writing paper for achieving repeatable “writing–erasing” applications.
Conductive organogels are considered ideal materials for the fabrication of flexible wearable electronic devices. However, the simultaneous realization of epidermal electronic devices with excellent self-healing, self-adhesion, multienvironment tolerance, and superior sensing performance remains a formidable challenge. In this study, a multiperformance conductive organogel was synthesized via a one-step photopolymerization of acrylic acid (AA) and acrylamide (AAm) in an H2O/glycerol (Gly) solution comprising gelatin and Al3+ ions, utilizing zinc dimethacrylate (ZDMA) containing Zn2+-carboxyl coordination bonds as an ionic cross-linker. The physical cross-linked gelatin/P(AA-co-AAm-co-ZDMA)/Al3+ organogel was formed through the synergistic effects of multiple hydrogen bonding, dual ionic coordination bonds, and physical entanglement among diverse macromolecular chains. The prepared organogel exhibited superior toughness (387 kPa), significant self-healing ability (633% strain for the healed organogel), prominent moisture retention (weight retention of 80% after 15 days), and remarkable long-term temperature resistance. Without sealed packaging, the organogel maintained excellent mechanical properties even after exposure to different temperatures (−30 °C, 20 °C, and 50 °C) for durations of 15, 15, and 7 days, respectively. The strain sensor based on the gelatin/P(AA-co-AAm-co-ZDMA)/Al3+ organogel exhibited excellent sensitivity (gauge factor, GF = 3.36), outstanding signal stability (600 cycles at 60% strain), and precise monitoring of underwater motion. The wireless heart monitoring system integrated with the organogel sensor was affixed to the left chest of volunteers for real-time detection of minute human electrocardiograph (ECG) signals. More notably, the synthesized organogel exhibited a pronounced alteration in transmittance upon exposure to water and glycerol, rendering it suitable for application as a reusable water writing paper for recording and erasing information. The multifunctional organogel exhibits great promise for the development of future flexible electronics with enhanced environmental adaptability.
危险品化学品经营许可证（带存储）