School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning, China.
State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
Soft Matter. 2022 Aug 10;18(31):5725-5741. doi: 10.1039/d2sm00519k.
Water-responsive (WR) materials, due to their controllable mechanical response to humidity without energy actuation, have attracted lots of attention to the development of smart actuators. WR material-based smart actuators can transform natural humidity to a required mechanical motion and have been widely used in various fields, such as soft robots, micro-generators, smart building materials, and textiles. In this paper, the development of smart actuators based on different WR materials has been reviewed systematically. First, the properties of different biological WR materials and the corresponding actuators are summarized, including plant materials, animal materials, and microorganism materials. Additionally, various synthetic WR materials and their related applications in smart actuators have also been introduced in detail, including hydrophilic polymers, graphene oxide, carbon nanotubes, and other synthetic materials. Finally, the challenges of the WR actuator are analyzed from the three perspectives of actuator design, control methods, and compatibility, and the potential solutions are also discussed. This paper may be useful for the development of not only soft actuators that are based on WR materials, but also smart materials applied to renewable energy.
水响应（WR）材料由于其能够对湿度进行可控的机械响应，而无需能源驱动，因此引起了人们对智能执行器发展的极大关注。基于 WR 材料的智能执行器可以将自然湿度转化为所需的机械运动，并已广泛应用于软机器人、微发电机、智能建材和纺织品等各个领域。本文系统地综述了基于不同 WR 材料的智能执行器的发展。首先，总结了不同生物 WR 材料及其相应执行器的特性，包括植物材料、动物材料和微生物材料。此外，还详细介绍了各种合成 WR 材料及其在智能执行器中的相关应用，包括亲水聚合物、氧化石墨烯、碳纳米管和其他合成材料。最后，从执行器设计、控制方法和兼容性三个角度分析了 WR 执行器的挑战，并讨论了潜在的解决方案。本文对于基于 WR 材料的软执行器的发展以及可再生能源应用的智能材料的发展可能具有一定的参考价值。
