Carbon Nanotubes/Hydrophobically Associated Hydrogels as Ultrastretchable, Highly Sensitive, Stable Strain, and Pressure Sensors
Carbon Nanotubes/Hydrophobically Associated Hydrogels as Ultrastretchable, Highly Sensitive, Stable Strain, and Pressure Sensors
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碳纳米管/疏水缔合水凝胶作为超可拉伸、高灵敏度、稳定的应变和压力传感器
DOI：
10.1021/acsami.9b21659
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发表时间：
2020-01-29
影响因子：
9.5
通讯作者：
Li, Junjie
中科院分区：
文献类型：
--
作者：
Qin, Zhihui;Sun, Xia;Li, Junjie
导电水凝胶由于具有良好的生物相容性和机械柔韧性，已成为最有前途的类皮肤传感器材料之一。然而，有限的延伸性、较低的韧性和抗疲劳性导致水凝胶传感器的传感范围较窄，耐久性不足。本工作通过将疏水碳纳米管(CNTs)与疏水缔合聚丙烯酰胺(HAPAAm)水凝胶进行复合，制备出极具延展性、高韧性和抗疲劳的纳米复合水凝胶。在这种导电水凝胶中，使用了两亲性的十二烷基硫酸钠来确保碳纳米管在水凝胶网络中的均匀分散，并在水凝胶基质和碳纳米管表面形成疏水相互作用，大大提高了水凝胶的力学性能。制得的CNTs/HAPAAm水凝胶具有良好的延伸性(约3000%)、韧性(3.42MJ·m~(-3))和良好的抗疲劳性能。此外，它在宽应变范围内(量规系数=4.32，最高可达1000%)表现出高的拉应变灵敏度，在0.127-50kPa的大压力范围内表现出高的线性灵敏度(1.00 kPa(-1))。基于CNTs/HAPAAm水凝胶的传感器可以灵敏而稳定地检测全方位的人类活动(如肘部旋转、手指弯曲、吞咽运动和发音)和手写，展示了CNTs/HAPAAm水凝胶作为柔性设备的可穿戴应变和压力传感器的潜力。
Conductive hydrogels have become one of the most promising materials for skin-like sensors because of their excellent biocompatibility and mechanical flexibility. However, the limited stretchability, low toughness, and fatigue resistance lead to a narrow sensing region and insufficient durability of the hydrogel-based sensors. In this work, an extremely stretchable, highly tough, and anti-fatigue conductive nanocomposite hydrogel is prepared by integrating hydrophobic carbon nanotubes (CNTs) into hydrophobically associated polyacrylamide (HAPAAm) hydrogel. In this conductive hydrogel, amphiphilic sodium dodecyl sulfate was used to ensure uniform dispersion of CNTs in the hydrogel network, and hydrophobic interactions between the hydrogel matrix and the CNT surface formed, greatly improving the mechanical properties of the hydrogel. The obtained CNTs/HAPAAm hydrogel showed excellent stretchability (ca. 3000%), toughness (3.42 MJ m(-3)), and great anti-fatigue property. Moreover, it exhibits both high tensile strain sensitivity in the wide strain ranges (gauge factor = 4.32, up to 1000%) and high linear sensitivity (0.127 kPa(-1)) in a large-pressure region within 0-50 kPa. The CNTs/HAPAAm hydrogel-based sensors can sensitively and stably detect full-range human activities (e.g., elbow rotation, finger bending, swallowing motion, and pronouncing) and handwriting, demonstrating the CNTs/HAPAAm hydrogel's potential as the wearable strain and pressure sensors for flexible devices.