Abstract：
To realize on stable and real-time monitoring of human activities, novel hydrogels using polyacrylic acid (PAA) and carboxymethyl guar gum (CMGG) were fabricated as wearable and flexible strain or pressure sensors in the presence of lignosulfonate (LS) and Al3+. Based on the co-existence of metal coordination bonds, hydrogen bonds and ionic interaction in this system, the obtained hydrogels exhibited desirable mechanical properties with good self-recovery ability. The hydrogels displayed good self-adhesion behavior and an ultra-high tensile sensitivity (gauge factor (GF) = 24.30), therefore, they could precisely detect human joints movements such as elbow, wrist, and finger bending as well as tiny movements and external stimuli such as swallowing, smile, frown, pulse, speaking, writing, and even the falling of different liquid drops. Additionally, the hydrogels showed excellent self-healing ability with the healing efficiency as high as 100 % after 30 h. Most importantly, the healed hydrogel could perform the same sensing performance as before. Based on these distinguished characteristics, this hydrogel represents great potentials in wearable and flexible sensors for long-term and stable health monitoring application.
摘要：
实现对人体活动的稳定、实时监测,在木质素磺酸盐（LS）和Al3存在的情况下，使用聚丙烯酸（PAA）和羧甲基瓜尔胶（CMGG）制造了新型水凝胶，作为可穿戴且柔性的应变或压力传感器。基于金属配位键的共存，该系统中的氢键和离子相互作用，所获得的水凝胶表现出理想的机械性能和良好的自恢复能力。水凝胶表现出良好的自粘附行为和超高的拉伸灵敏度（应变系数（GF）=24.30），因此,它们可以精确检测人体关节的运动，如肘部，手腕,手指弯曲以及微小的运动和外部刺激，如吞咽，微笑，皱眉,脉搏,说话,写作,甚至不同液滴的下落。此外,30h后，水凝胶显示出优异的自修复能力，愈合效率高达100％。最重要的是，愈合的水凝胶可以执行与以前相同的传感性能。基于这些显著特征,这种水凝胶代表了长期和稳定的健康监测应用可穿戴和柔性传感器的巨大潜力。
