Li Mu, Zhang Tao, Zhang Xiang, Mu Jinjiang, Zhang Weiwei
Department of Pharmacy, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
School of Mechanical Engineering, Zhengzhou University, Zhengzhou, China.
Front Bioeng Biotechnol. 2022 Apr 25;10:877964. doi: 10.3389/fbioe.2022.877964. eCollection 2022.
Inspired by the biological collective behaviors of nature, artificial microrobotic swarms have exhibited environmental adaptability and tasking capabilities for biomedicine and micromanipulation. Complex environments are extremely relevant to the applications of microswarms, which are expected to travel in blood vessels, reproductive and digestive tracts, and microfluidic chips. Here we present a strategy that reconfigures paramagnetic nanoparticles into a vector-controlled microswarm with 3D collective motions by programming sawtooth magnetic fields. Horizontal swarms can be manipulated to stand vertically and swim like a wheel by adjusting the direction of magnetic-field plane. Compared with horizontal swarms, vertical wheel-like swarms were evaluated to be of approximately 15-fold speed increase and enhanced maneuverability, which was exhibited by striding across complex 3D confinements. Based on analysis of collective behavior of magnetic particles in flow field using molecular dynamics methods, a rotary stepping mechanism was proposed to address the formation and locomotion mechanisms of wheel-like swarm. we present a strategy that actuates swarms to stand and hover under a programming swing magnetic fields, which provides suitable solutions to travel across confined space with unexpected changes, such as stepped pipes. By biomimetic design from fin motion of fish, wheel-like swarms were endowed with multi-modal locomotion and load-carrying capabilities. This design of intelligent microswarms that adapt to complicated biological environments can promote the applications ranging from the construction of smart and multifunctional materials to biomedical engineering.
受自然界生物集体行为的启发，人工微型机器人集群已展现出在生物医学和微操作方面的环境适应性和任务执行能力。复杂环境与微型机器人集群的应用密切相关，这些集群有望在血管、生殖和消化道以及微流控芯片中运行。在此，我们提出一种策略，通过对锯齿形磁场进行编程，将顺磁性纳米粒子重新配置成具有三维集体运动的矢量控制微型机器人集群。通过调整磁场平面方向，可操控水平集群垂直站立并像轮子一样游动。与水平集群相比，垂直轮状集群的速度提高了约15倍，机动性增强，这通过跨越复杂的三维限制得以体现。基于分子动力学方法对流场中磁性粒子集体行为的分析，提出了一种旋转步进机制来解释轮状集群的形成和运动机制。我们提出一种策略，在编程的摆动磁场作用下驱动集群站立和悬停，这为穿越诸如阶梯管道等具有意外变化的受限空间提供了合适的解决方案。通过模仿鱼类鳍的运动进行仿生设计，轮状集群具备了多模态运动和负载能力。这种适应复杂生物环境的智能微型机器人集群设计可推动从智能和多功能材料构建到生物医学工程等一系列应用。
