Stable Droplet Manipulation in Multiple Directions on a Magnetically Responsive Micropillar Array Surface

Abstract Droplets constitute an essential discrete form of liquids and are prevalent in both natural and industrial fields. Droplet manipulation technologies have broad application prospects in various fields, including biomedical devices, chemical engineering, water collection, and so on. The manipulation of surfaces with magnetic responsiveness has emerged as a pivotal technique in droplet control owing to its flexibility and precision in remote operations. In this study, the dynamic rolling behavior of low‐surface‐tension working fluids and water droplets on a superhydrophobic magnetically responsive micropillar array (SMMA) is investigated, with a focus on the mechanisms that generate instabilities during the directional rolling motion of droplets. The factors influencing these instabilities are studied using data analysis. Moreover, techniques for capturing and releasing droplets are investigated, offering significant insights into the efficient handling of minute amounts of liquids in experiments and the automation of intricate chemical processes.