Fluid-Mediated Fabrication of Complex Assemblies

Abstract

This Perspective accounts for recent progress in the directed control of interfacial fluid flows harnessed to assemble architected soft materials. We are focusing on the paradigmatic problem of free-surface flows in curable elastomers. These elastomers are initially liquid and cure into elastic solids whose shape is imparted by concomitant and competing phenomena: flowinduced deformations and curing. Particular attention is given to the role of capillary forces in these systems. Originating from the cohesive nature of liquids and thus favoring smooth interfaces, capillary forces can also promote the destabilization of interfaces, e.g., into droplets. In turn, such mechanical instabilities tend to grow into regular patterns, e.g., forming hexagonal lattices. We discuss how the universality, robustness, and ultimate regularity of these out-of-equilibrium processes could serve as a basis for new fabrication paradigms, where instabilities are directed to generate target architected solids obtained without each element laid in place by direct mechanized intervention.

Exploiting breath figure reversibility for in situ pattern modulation and hierarchical design

“…[6][7][8] Full exploitation of such biomimetic fabrication methods towards predictive surface patterning, however, relies upon the understanding and taming of the underlying complex multiphysics phenomena. 9 Here, we explore the possibility of tuning the surface architecture achieved through the wellknown breath figure (BF) templating approach by exploiting the reversibility of the phase change process that governs the operation.…”