Shi Huiwen, Wang Xin, Guo Huijun, Yang Yanyan, Yang Yongqi
School of Materials Science and Engineering, Jilin Institute of Chemical Technology, Jilin 132022, China.
School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin 132022, China.
ACS Appl Mater Interfaces. 2024 Sep 4;16(35):46810-46821. doi: 10.1021/acsami.4c10826. Epub 2024 Aug 23.
Optical camouflage offers an effective strategy for enhancing the survival chances of underwater flexible electronic devices akin to underwater organisms. Photochromism is one of the most effective methods to achieve optical camouflage. In this study, antiswelling hydrogels with photochromic properties were prepared using a two-step solvent replacement strategy and explored as underwater optically camouflaged flexible electronic devices. The hydrophobic network formed upon polymerization of hydroxyethyl methacrylate (HEMA) ensured that the hydrogels possessed outstanding antiswelling properties. Internetwork hydrogen bonding interactions allowed the hydrogels to exhibit tissue-adaptable mechanical properties and excellent self-bonding capabilities. The introduction of polyoxometalates further enhanced the hydrogels' mechanical and self-bonding properties while imparting photochromic capability. The hydrogels could be rapidly and reversibly colored under 365 nm UV irradiation. The bleaching rate of the colored hydrogels increased with temperature, bleaching within 12 h at 60 °C but maintaining the color for more than 5 days at room temperature. The self-bonding and photochromic properties enabled the hydrogels to be easily assembled into optically camouflaged underwater flexible electronic devices for underwater motion sensing and wireless information transmission. An optically camouflaged strain sensor was first assembled for underwater limb motion sensing. Additionally, an underwater optically camouflaged wireless information exchange device was assembled to enable wireless communication with a smartphone. This work provided an effective strategy for the optical camouflage of underwater flexible electronic devices, presenting opportunities for next-generation underwater hydrogel-based flexible devices.
光学伪装为提高水下柔性电子设备（类似于水下生物）的生存几率提供了一种有效策略。光致变色是实现光学伪装最有效的方法之一。在本研究中，采用两步溶剂置换策略制备了具有光致变色特性的抗溶胀水凝胶，并将其作为水下光学伪装柔性电子设备进行探索。甲基丙烯酸羟乙酯（HEMA）聚合时形成的疏水网络确保水凝胶具有出色的抗溶胀性能。网络间的氢键相互作用使水凝胶表现出与组织相适应的机械性能和优异的自粘合能力。多金属氧酸盐的引入进一步增强了水凝胶的机械性能和自粘合性能，同时赋予其光致变色能力。水凝胶在365 nm紫外线照射下可快速、可逆地变色。着色水凝胶的漂白速率随温度升高而增加，在60℃下12小时内漂白，但在室温下可保持颜色超过5天。自粘合和光致变色特性使水凝胶能够轻松组装成用于水下运动传感和无线信息传输的光学伪装水下柔性电子设备。首先组装了一种用于水下肢体运动传感的光学伪装应变传感器。此外，还组装了一种水下光学伪装无线信息交换设备，以实现与智能手机的无线通信。这项工作为水下柔性电子设备的光学伪装提供了一种有效策略，为下一代基于水凝胶的水下柔性设备带来了机遇。
