Lei Tongda, Wang Yongheng, Feng Yaya, Duan Xingru, Zhang Qingsong, Wan Ailan, Xia Zhaopeng, Shou Wan, Fan Jie
School of Textile Science and Engineering, Tiangong University, Tianjin 300387, China.
Medical Experimental Center, North China University of Science and Technology, Tangshan, China.
J Colloid Interface Sci. 2025 Jan 15;678(Pt C):726-741. doi: 10.1016/j.jcis.2024.09.131. Epub 2024 Sep 17.
Conductive hydrogels have received much attention in the field of flexible wearable sensors due to their outstanding flexibility, conductivity, sensitivity and excellent compatibility. However, most conductive hydrogels mainly focus on strain sensors to detect human motion and lack other features such as temperature response. Herein, we prepared a strain and temperature dual responsive ionic conductive hydrogel (PPPNV) with an interpenetrating network structure by introducing a covalent crosslinked network of N-isopropylacrylamide (NIPAAm) and 1-vinyl-3-butylimidazolium bromide (VBIMBr) into the skeleton of the hydrogel composed of polyvinylalcohol (PVA) and polyvinylpyrrolidone (PVP). The PPPNV hydrogel exhibited excellent anti-freezing properties (-37.34 °C) and water retention with high stretchability (∼930 %) and excellent adhesion. As a wearable strain sensor, the PPPNV hydrogel has good responsiveness and stability to a wide range of deformations and exhibits high strain sensitivity (GF=2.6) as well as fast response time. It can detect large and subtle body movements with good signal stability. As wearable temperature sensors, PPPNV hydrogels can detect human physiological signals and respond to temperature changes, and the volumetric phase transition temperature (VPTT) can be easily controlled by adjusting the molar ratio of NIPAAm to VBIMBr. In addition, a bilayer temperature-sensitive hydrogel was prepared with the temperature responsive hydrogel by two-step synthesis, which shows great promising applications in temperature actuators.
由于具有出色的柔韧性、导电性、灵敏度和优异的兼容性，导电水凝胶在柔性可穿戴传感器领域备受关注。然而，大多数导电水凝胶主要集中在应变传感器以检测人体运动，缺乏温度响应等其他特性。在此，我们通过将N-异丙基丙烯酰胺（NIPAAm）和1-乙烯基-3-丁基咪唑溴盐（VBIMBr）的共价交联网络引入由聚乙烯醇（PVA）和聚乙烯吡咯烷酮（PVP）组成的水凝胶骨架中，制备了一种具有互穿网络结构的应变和温度双响应离子导电水凝胶（PPPNV）。PPPNV水凝胶表现出优异的抗冻性能（-37.34℃）和保水性，具有高拉伸性（~930%）和优异的粘附性。作为可穿戴应变传感器，PPPNV水凝胶对广泛的变形具有良好的响应性和稳定性，表现出高应变灵敏度（GF=2.6）以及快速响应时间。它能够以良好的信号稳定性检测大幅度和细微的身体运动。作为可穿戴温度传感器，PPPNV水凝胶能够检测人体生理信号并对温度变化做出响应，并且通过调节NIPAAm与VBIMBr的摩尔比可以轻松控制体积相变温度（VPTT）。此外，通过两步合成法用温度响应水凝胶制备了双层温度敏感水凝胶，其在温度致动器方面显示出极具前景的应用。
