Self-assembly of nanoscale braided structures

Capillarity, along with bending and cohesive forces, can induce assembly of nanopillar/micropillar arrays into a wide variety of structures. Experiments we performed involving seven hexagonally arranged pillars reveal a surprising transition from straight to twisted conformations. Separately, we also found that large arrays (e.g. 30x30, 10x40) of high-aspect ratio pillars can assemble into various structures, including chiral, globally twisted morphologies. Here we use numerical and scaling methods to understand how the rate of drying, capillarity, bending, and cohesion control the physics of elastocapillary-driven self-assembly.