National Engineering Research Center for Colloidal Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, Shandong, China.
Langmuir. 2022 Dec 13;38(49):15433-15441. doi: 10.1021/acs.langmuir.2c02853. Epub 2022 Dec 2.
Most soft actuators have the ability of monotonic responsiveness. That is, there is only one response action after being stimulated once. In this work, a temporarily responsive bilayer hydrogel actuator is designed and fabricated by combining a tertiary amine-containing pH-responsive layer and a urease-containing non-responsive layer. The hydrogel actuator can achieve programed deformation and recovery driven by chemical fuels (i.e., acidic urea solutions), which is essentially regulated by rapid acidification and slow enzymatic production of ammonia for recovering the pH of the system. The actuation extent and duration can be simply controlled by the fuel levels, and the repeated actuations are also possible via refueling. Furthermore, we fabricate several hydrogel devices that can display specific patterns or lift an item. This enzymatic method shows new possibilities to control the temporary actuation of polymer hydrogels potentially useful in many fields such as soft robotics, biomimetic devices, and environmental sensing.
大多数软执行器具有单调响应的能力。也就是说，受到刺激后只会有一次响应动作。在这项工作中，通过将含叔胺的 pH 响应层和含脲酶的非响应层组合，设计并制备了一种暂时响应的双层水凝胶执行器。该水凝胶执行器可以通过化学燃料（即酸性尿素溶液）实现程序化变形和恢复，这主要是通过快速酸化和缓慢酶促生成氨来恢复系统的 pH 值来调节的。通过控制燃料的水平，就可以简单地控制致动程度和持续时间，并且通过重新加油也可以实现重复致动。此外，我们还制造了一些可以显示特定图案或提升物品的水凝胶器件。这种酶法为控制聚合物水凝胶的暂时致动提供了新的可能性，这在软机器人、仿生装置和环境感应等许多领域可能具有潜在的应用价值。
