Low-Friction Self-Centering Droplet Propulsion and Transport Using a Leidenfrost Herringbone-Ratchet Structure
Low-Friction Self-Centering Droplet Propulsion and Transport Using a Leidenfrost Herringbone-Ratchet Structure
复制标题
DOI：
10.1103/physrevapplied.11.034063
复制
发表时间：
2019-03-27
影响因子：
4.6
通讯作者：
Wood, David
中科院分区：
文献类型：
--
作者：
Dodd, Linzi E.;Agrawal, Prashant;Wood, David
运输固着液滴的能力的基本限制是由表面粘附引起的摩擦力。这可以通过在加热的基底上使用莱顿弗罗斯特效应将液滴悬浮在蒸汽垫上来克服。通过构造液滴下方的表面，可以控制液滴下方的蒸汽流，并且这可以用于诱导在特定方向上的优先液滴推进。然而，虽然可以诱导推进，但摩擦力的急剧减小导致不稳定，并且当沿限定路径沿着输送液滴时难以控制液滴运动。在这里，我们提出了一种使用负反馈原理的自推进和自定心概念，以使液滴能够沿限定路径沿着输送。在我们的实现中，我们使用组合的人字形和棘轮设计，这提供了在不损害速度的情况下控制液滴位置的能力。这种内在的自定心和通过负反馈的校正提供了设计液滴跟随的路径和轨道的可能性，而不需要壁。
A fundamental limitation to the ability to transport sessile droplets is frictional forces arising from surface adhesion. This can be overcome by using the Leidenfrost effect on a heated substrate to levitate the droplet on a cushion of vapor. By structuring the surface under the droplet, the flow of vapor below the droplet can be controlled and this can be used to induce preferential droplet propulsion in a particular direction. However, while propulsion can be induced, the dramatic reduction in frictional forces leads to instability and it is difficult to control droplet motion when transporting droplets along a defined path. Here, we present a self-propulsion and self-centering concept using the principles of negative feedback to enable a droplet to be transported along a defined path. In our implementation, we use a combined herringbone and ratchet design, which provides the ability to control droplet position without compromising on speed. This intrinsic self-centering and correction via negative feedback offers the potential to design paths and tracks for droplets to follow, without the need for walls.