The design of synthetic hydrogels capable of exhibiting smart adaptive behaviors in response to light has gained significant interest to mimic the dynamic structures and functions as we observed in nature. Here we report on the molecular design of a photoresponsive hydrogel by covalently integrating oxazine-based compounds into the crosslinked polymer network through a free radical copolymerization strategy. The resultant oxazine hydrogels are found to be able to display well-controlled temperature variation through a photothermal effect in response to external irradiation with visible light. The light-induced non-uniform temperature variation of these hydrogels at the water-air interface lead to the generation of Marangoni propulsion, which subsequently drives them move as a swimmer. In addition to unidirectional swimming, such hydrogel swimmers are able to display steering, rotating, path-following motion and cargo transporting function by control of external irradiation parameters. Our work provides a useful molecular design strategy for development of other photoactive hydrogels with applications in smart actuators and soft robotics.

能够响应光而表现出智能自适应行为的合成水凝胶的设计引起了人们对模仿我们在自然界中观察到的动态结构和功能的极大兴趣。在这里，我们报告了通过自由基共聚策略将恶嗪基化合物共价整合到交联聚合物网络中的光响应水凝胶的分子设计。发现所得的恶嗪水凝胶能够通过响应可见光外部照射的光热效应显示出良好控制的温度变化。这些水凝胶在水-空气界面处的光诱导的不均匀温度变化导致马兰戈尼推进力的产生，随后驱动它们像游泳者一样移动。除了单向游泳之外，这种水凝胶游泳器能够通过控制外部照射参数来显示转向、旋转、路径跟随运动和货物运输功能。我们的工作为开发其他光敏水凝胶及其在智能执行器和软机器人中的应用提供了有用的分子设计策略。