Polymeric and Soft Materials Laboratory, School of Chemical Engineering and Advanced Institute of Materials Science, Changchun University of Technology, Changchun 130012, China.
J Mater Chem B. 2019 Jul 31;7(30):4638-4648. doi: 10.1039/c9tb01039d.
The advent of hydrogel-based strain sensors has attracted immense research interest in artificial intelligence, wearable devices, and health-monitoring systems. However, the integration of the synergistic characteristics of good mechanical properties, self-adhesiveness, self-healing capability and high strain sensitivity for fabricating hydrogel-based strain sensors is still a challenge. Here, a multifunctional conductive hydrogel composed of a polyacrylamide (PAAm)/chitosan (CS) hybrid network is fabricated for wearable strain sensors. The PAAm network is cross-linked by hydrophobic associations, and the CS network is ionically cross-linked by carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs). These two networks are further interlocked by physical entanglement and hydrogen bond interactions. The obtained hydrogels exhibit excellent flexibility, puncture resistance and self-healing capability because of the efficient energy dissipation of the dynamic cross-linking network. Moreover, the hydrogels exhibit self-adhesive behavior on various materials, including polytetrafluoroethylene, wood, glass, aluminum, rubber and skin. Notably, the hydrogels can be applied as soft human-motion sensors for real-time and accurate detection of both large-scale and small human activities, including joint motions, speaking, breathing, and even subtle blood pulsation. Therefore, it is anticipated that the flexible, self-adhesive, self-healing and conductive hydrogel-based strain sensor will have promising applications in artificial intelligence, soft robots, biomimetic prostheses, and personal health care.
水凝胶基应变传感器的出现引起了人工智能、可穿戴设备和健康监测系统领域的极大研究兴趣。然而，将良好的机械性能、自粘性、自修复能力和高应变灵敏度的协同特性集成到水凝胶基应变传感器的制造中仍然是一个挑战。在这里，我们制备了一种由聚丙烯酰胺（PAAm）/壳聚糖（CS）杂化网络组成的多功能导电水凝胶，用于可穿戴应变传感器。PAAm 网络通过疏水缔合交联，CS 网络通过羧基功能化多壁碳纳米管（c-MWCNTs）离子交联。这两个网络通过物理缠结和氢键相互作用进一步联锁。由于动态交联网络的有效能量耗散，所得到的水凝胶表现出优异的柔韧性、耐穿刺性和自修复能力。此外，水凝胶对各种材料表现出自粘性行为，包括聚四氟乙烯、木材、玻璃、铝、橡胶和皮肤。值得注意的是，水凝胶可用作软人体运动传感器，用于实时、准确地检测包括关节运动、说话、呼吸甚至微妙的血液搏动在内的各种大、小动作。因此，预计具有灵活、自粘性、自修复和导电的水凝胶基应变传感器将在人工智能、软机器人、仿生假肢和个人健康护理等领域具有广阔的应用前景。
