论文标题
将弹性磁盘捕集为微武器：通过形状滞后在低雷诺数下游泳
Snapping elastic disks as microswimmers: swimming at low Reynolds numbers by shape hysteresis
论文作者
论文摘要
我们说明了一个改变形状变化的微武器的概念，该概念通过经历环状局部肿胀的弹性盘来利用弹性对象的形状转变的滞后。如果将弹性物体浸入粘性液中，则以完全可逆的方式驱动滞后形状转变的控制参数会产生非时间可逆的形状序列和净游泳运动。我们用微型磁盘证明了这一概念，该磁盘是一个平坦的圆盘磁盘，通过内部磁盘的局部肿胀将过渡到圆顶状的形状。这种形状转换的控制参数是磁盘材料的标量肿胀因子。在固定的外部框架中，中央区域具有附加的吸引人相互作用，平坦和圆顶状形之间的形状过渡变成了滞后，并且类似于扇贝的滞后开口和闭合。使用Stokesian动力学模拟该磁盘的离散版本，我们表明，如果以时间可逆的方式更改了溶胀参数，则游泳者正在有效地进入圆顶液体开口的方向。游泳机制可以通过简单的9珠模型定性地重现。
We illustrate a concept for shape-changing microswimmers, which exploits the hysteresis of a shape transition of an elastic object, by an elastic disk undergoing cyclic localized swelling. Driving the control parameter of a hysteretic shape transition in a completely time-reversible manner gives rise to a non-time-reversible shape sequence and a net swimming motion if the elastic object is immersed into a viscous fluid. We prove this concept with a microswimmer which is a flat circular elastic disk that undergoes a transition into a dome-like shape by localized swelling of an inner disk. The control parameter of this shape transition is a scalar swelling factor of the disk material. With a fixed outer frame with an additional attractive interaction in the central region, the shape transition between flat and dome-like shape becomes hysteretic and resembles a hysteretic opening and closing of a scallop. Employing Stokesian dynamics simulations of a discretized version of the disk we show that the swimmer is effectively moving into the direction of the opening of the dome in a viscous fluid if the swelling parameter is changed in a time-reversible manner. The swimming mechanism can be qualitatively reproduced by a simple 9-bead model.
