The design of soft matter in which internal fuels or an external energy input can generate locomotion and shape transformations observed in living organisms is a key challenge. Such materials could assist in productive functions that may range from robotics to smart management of chemical reactions and communication with cells. In this context, hydrated matter that can function in aqueous media would be of great interest. Here, we report the design of hydrogels containing a scaffold of high–aspect ratio ferromagnetic nanowires with nematic order dispersed in a polymer network that change shape in response to light and experience torques in rotating magnetic fields. The synergistic response enables fast walking motion of macroscopic objects in water on either flat or inclined surfaces and also guides delivery of cargo through rolling motion and light-driven shape changes. The theoretical description of the response to the external energy input allowed us to program specific trajectories of hydrogel objects that were verified experimentally.

一个关键的挑战是设计软物质，其中内部燃料或外部能量输入可以产生在生物体内观察到的运动和形状转换。此类材料可以辅助生产功能，其功能可能从机器人技术到化学反应的智能管理以及与细胞的通讯。在这方面，可以在水性介质中起作用的水合物质将引起极大的兴趣。在这里，我们报告了一种水凝胶的设计，该水凝胶包含高纵横比的铁磁纳米线支架，该支架具有向列顺序分散在聚合物网络中，该聚合物网络可响应光而改变形状并在旋转磁场中经受扭矩。协同响应可以使宏观物体在水中在平坦或倾斜表面上快速行走，并通过滚动运动和光驱动的形状变化引导货物运输。对外部能量输入的响应的理论描述使我们能够对水凝胶物体的特定轨迹进行编程，这些轨迹已通过实验验证。