Zheng Jingxia, Chen Guoqi, Yang Hailong, Zhu Canjie, Li Shengnan, Wang Wenquan, Ren Jiayuan, Cong Yang, Xu Xun, Wang Xinwei, Fu Jun
Key Laboratory of Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Functional Biomaterials Engineering Technology Research Center, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, China.
Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou 510055, China.
Mater Horiz. 2023 Oct 2;10(10):4232-4242. doi: 10.1039/d3mh00718a.
Hydrogel-based wearable flexible pressure sensors have great promise in human health and motion monitoring. However, it remains a great challenge to significantly improve the toughness, sensitivity and stability of hydrogel sensors. Here, we demonstrate the fabrication of hierarchically structured hydrogel sensors by 3D printing microgel-reinforced double network (MRDN) hydrogels to achieve both very high sensitivity and mechanical toughness. Polyelectrolyte microgels are used as building blocks, which are interpenetrated with a second network, to construct super tough hydrogels. The obtained hydrogels show a tensile strength of 1.61 MPa, and a fracture toughness of 5.08 MJ m with high water content. The MRDN hydrogel precursors exhibit reversible gel-sol transitions, and serve as ideal inks for 3D printing microstructured sensor arrays with high fidelity and precision. The microstructured hydrogel sensors show an ultra-high sensitivity of 0.925 kPa, more than 50 times that of plain hydrogel sensors. The hydrogel sensors are assembled as an array onto a shoe-pad to monitor foot biomechanics during gaiting. Moreover, a sensor array with a well-arranged spatial distribution of sensor pixels with different microstructures and sensitivities is fabricated to track the trajectory of a crawling tortoise. Such hydrogel sensors have promising application in flexible wearable electronic devices.
基于水凝胶的可穿戴柔性压力传感器在人体健康和运动监测方面具有巨大潜力。然而，要显著提高水凝胶传感器的韧性、灵敏度和稳定性仍然是一个巨大的挑战。在此，我们展示了通过3D打印微凝胶增强双网络（MRDN）水凝胶来制造分层结构的水凝胶传感器，以实现非常高的灵敏度和机械韧性。聚电解质微凝胶用作构建块，与第二网络相互贯穿，以构建超强韧性水凝胶。所获得的水凝胶在高含水量下表现出1.61 MPa的拉伸强度和5.08 MJ m的断裂韧性。MRDN水凝胶前体表现出可逆的凝胶 - 溶胶转变，并作为用于3D打印具有高保真度和精度的微结构化传感器阵列的理想墨水。微结构化水凝胶传感器显示出0.925 kPa的超高灵敏度，是普通水凝胶传感器的50多倍。水凝胶传感器被组装成阵列安装在鞋垫上，以监测步态期间的足部生物力学。此外，还制造了一种具有不同微结构和灵敏度的传感器像素空间分布排列良好的传感器阵列，以跟踪爬行乌龟的轨迹。这种水凝胶传感器在柔性可穿戴电子设备中具有广阔的应用前景。
