论文标题
平面起伏的磁性微晶体器的非线性动力学和分叉
Nonlinear dynamics and bifurcations of a planar undulating magnetic microswimmer
论文作者
论文摘要
游泳微生物（例如鞭毛细菌和精子细胞）具有引人入胜的运动能力。受其自然运动的启发，持续不断地开发人工机器人纳米驱动器，以实现潜在的体内生物医学应用。纳米 - 温植物驱动的领先方法是应用时间变化的外部磁场。这样的系统具有丰富的非线性动态，需要简单的基本模型。先前的工作研究了一个具有被动弹性关节的简单两连锁模型的正向运动，假设磁场的较小振幅平面振荡在恒定方向上。在这项工作中，我们发现游泳者具有非常丰富的动态的速度更快，落后。通过放松小振幅假设，我们分析了周期性解决方案的多样性及其分叉，对称性破坏和稳定性转变。我们还发现，净位移和/或平均游泳速度可最大化，以选择各种参数。针对分叉条件和游泳者的平均速度进行了渐近计算。该结果可能会显着改善磁性机器人微功能的设计方面。
Swimming micro-organisms such as flagellated bacteria and sperm cells have fascinating locomotion capabilities. Inspired by their natural motion, there is an ongoing effort to develop artificial robotic nano-swimmers for potential in-body biomedical applications. A leading method for actuation of nano-swimmers is by applying a time-varying external magnetic field. Such systems have rich and nonlinear dynamics that calls for simple fundamental models. A previous work studied forward motion of a simple two-link model with passive elastic joint, assuming small-amplitude planar oscillations of the magnetic field about a constant direction. In this work, we found that there exists a faster, backward motion of the swimmer with very rich dynamics. By relaxing the small-amplitude assumption, we analyze the multiplicity of periodic solutions, as well as their bifurcations, symmetry breaking, and stability transitions. We have also found that the net displacement and/or mean swimming speed are maximized for optimal choices of various parameters. Asymptotic calculations are performed for the bifurcation condition and the swimmer's mean speed. The results may enable significantly improving the design aspects of magnetically-actuated robotic microswimmer.
