基于高强度智能水凝胶的仿生柔性驱动器的设计与驱动模式研究

Hydrogel soft actuators are bioinspired smart machines that could accomplish designed actions under the actuation of external energy, which have already attracted numerous studies due to their large amplitude stimuli-response and easy adjustment. However, the actuating accuracy was low due to the poor mechanical strength of traditional hydrogels, as well as small amount of action mode. The presence of several kinds of tough hydrogels recently makes the hydrogels achieve more accurate deformation, but there was no system study in bioinspired soft actuators based on these tough hydrogels. This proposal will focus on the bioinspired soft actuators based on these tough hydrogels and our study in tough nano-hybrid hydrogels. Hydrogel actuating components which could realize designed basic actions accurately such as bending, extending or rotating will be prepared with the inspiration of natural structures and functions. Functional components with releasing or detecting functions will also be designed. The components will be combined three dimensionally according to bioinspired form to obtain soft actuators with the function of designed accurate actuating and multiple functions. The actuating mode and mechanism will studied systematically to propose a universal method for designing soft composite actuators. We expect this study could offer new methods in designing and preparing soft actuators.

水凝胶柔性驱动器是在外界能量驱动下产生所需动作的仿生智能软物质机器，由于智能水凝胶的刺激-响应动作大、易调控而受到广泛关注。但目前的水凝胶驱动器由于凝胶强度弱，导致驱动精度较低，且运动模式少；近年来出现的高强度智能水凝胶可实现较为精确的形变，但基于高强度水凝胶的仿生柔性驱动器尚未有系统研究。本项目拟从仿生学原理出发，结合申请者关于高强度纳米杂化水凝胶的研究基础和其它几类高强度智能水凝胶，借助仿生结构和功能，设计在简便易行的能量驱动下可精准完成弯曲、伸展、旋转等基本动作的水凝胶驱动部件以及具有释放、探测等特性的功能部件；并将各部件按照仿生学的方式进行3D整合，制备出实现精准可控的柔性运动并具有多种功能性的水凝胶仿生复合驱动器；对驱动模式和机理进行探索和系统化，尝试给出普适性的水凝胶复合驱动器设计方法，为柔性驱动器的设计和制备提供新的方法和理论基础。

高强度刺激-响应水凝胶以其优异的力学性能、多样的刺激-响应行为、灵活可控的驱动方式，在柔性驱动器的制备中发挥着重要作用。在众多种类的响应性水凝胶中，形状记忆水凝胶在接受外界刺激后，可自发地由临时形状转换为永久形状，在形状改变过程中产生的驱动力及动作变化可以使其作为柔性驱动器的结构部件；此外，构建各向异性的水凝胶组合体，可将各向同性的水凝胶溶胀和收缩行为，转换为各向异性的运动，也是设计水凝胶柔性驱动器的便捷途径。本项目以高强度刺激-响应性形状记忆水凝胶为出发点，筛选了温度、近红外激光、溶剂、pH及金属离子响应等多种高强度水凝胶驱动部件；通过宏观拉伸、动态粘弹谱、溶胀行为，微观电镜等表征手段，同时借助粘弹塑模型对高强度水凝胶的机械性能进行了描述，对水凝胶驱动器的微观结构、驱动机理等方面进行了系统研究；以粘性、自修复等方式构建了基于形状记忆、Janus多层结构的多种刺激-响应性水凝胶柔性驱动器，并提出水凝胶-干凝胶、水凝胶-聚合物复合驱动体系的设计理念；探索发现了形状记忆水凝胶的自发驱动行为，为制备可连续驱动的水凝胶柔性驱动器提供理想的驱动部件。本项目研究结果为刺激-响应性柔性驱动器的设计、制备和表征等方面提供了系统的实验和理论基础。