Research Institute of Materials Science and ‡State Key Laboratory of Luminescent Materials and Devices, South China University of Technology , Guangzhou 510640, China.
ACS Appl Mater Interfaces. 2017 Apr 5;9(13):11866-11873. doi: 10.1021/acsami.7b00138. Epub 2017 Mar 24.
Facile preparation, rapid actuating, and versatile actions are great challenges in exploring new kinds of hydrogel actuators. In this paper, we presented a facile sticking method to prepare Janus bilayer and multilayer hydrogel actuators that benefited from a special tough and adhesive PAA-clay hydrogel. Combining physical and chemical cross-linking reagents, we endowed the PAA gel with both toughness and adhesion. This PAA gel was reinforced by further cross-linking with Fe. These two hydrogels with different cross-linking densities exhibited different swelling capabilities and moduli in the media manipulated by pH and ionic strength, thus acting as promising candidates for soft actuators. On the basis of these gels, we designed hydrogel actuators of rapid response in several minutes and precisely controlled actuating direction by sticking two hydrogel layers together. Elaborate soft actuators such as bidirectional bending flytrap, gel hand with grasp, open, and gesturing actions as well as word-writing actuator were prepared. This method could be generalized by using other stimuli-responsive hydrogels combined with the adhesive PAA gel, which would open a new way to programmable and versatile soft actuators.
制备简便、响应迅速且多功能化是开发新型水凝胶驱动器的巨大挑战。本文提出了一种简便的贴合方法，用于制备 Janus 双层和多层水凝胶驱动器，该方法得益于一种特殊的坚韧且粘性的 PAA-黏土水凝胶。通过物理和化学交联试剂的结合，我们赋予 PAA 凝胶韧性和粘性。进一步用 Fe 进行交联，可增强这种 PAA 凝胶。这两种交联密度不同的水凝胶在 pH 值和离子强度调控的介质中表现出不同的溶胀能力和模量，因此有望成为软驱动器的候选材料。基于这些水凝胶，我们通过将两层水凝胶贴合在一起，设计了快速响应的水凝胶驱动器，并精确控制驱动方向。我们还制备了复杂的软驱动器，例如双向弯曲的捕蝇草、具有抓握、张开和手势功能的凝胶手以及写字的驱动器。通过使用其他刺激响应水凝胶与粘性 PAA 凝胶相结合，这种方法可以被推广，为可编程和多功能化的软驱动器开辟了新途径。
