Multi-functional fin texture controlled by dynamic elastocapillary effect

Soft fins can deform by the elastocapillary effect which originates from the surface tension of liquid menisci. We design reconfigurable surface textures consisting of fins with polymorphic self-assembly mode shapes controlled by dynamic fluid drainage. We discovered that the self-assembly mode shapes are selected by fluid dynamics, which is different from conventional systems that only have single mode shape for one geometry. In the presentation, we will first describe the design and fabrication of slender single and multiple fin geometries using molds produced by additive manufacturing. Next, the fin bending mechanism is explained by theoretical scaling laws that capture the phenomena on various fin geometries, including their length and the spacing between the fins and the walls. Lastly, some application of reconfigurable texture, such as letter display and message encoding in optical and IR regime, will be shown.