Magnetically reconfigurable multistable ribbon arrays for liquid manipulation

We present a liquid manipulation device built with magnetically reconfigurable multistable ribbons, fabricated through compressive buckling of magnetic polydimethylsiloxane films. These ribbons transition among three locally stable states via magnetic actuation and can retain their states without constant external fields. We first design a switchable fluid junction and demonstrate on-demand control of outlet flow directions in a two-dimensional (2D) fluid channel. We then extend this concept to dynamic surface textures formed by ribbon arrays, where tuning individual ribbon states modulates critical angles for controlling droplet pinning and release. Using a 3 × 2 ribbon array as an example, we show that controlling individual ribbon states further enables complex droplet manipulations. We perform mesoscale simulations with coupled electrocapillary models, providing theoretical foundations for more complex device designs and configurations.