(579e) Complex Tessellations By the Sequential Assembly of Soft Colloids

Colloidal monolayers are emerging as an attractive means to fabricate two-dimensional (2D) patterns with promising applications in fields ranging from optoelectronics and biology to metamaterials. In particular, complex tessellations such as Archimedean and non-regular tilings promise unprecedented structure-dependent properties. Yet, obtaining colloidal monolayers in arrangements beyond the hexagonal tiling remains challenging. In fact, more complex patterns typically require involved procedures and/or colloidal particles presenting tailored geometries or patchy surfaces that introduce well-defined directional interactions. Here, using experiments and molecular dynamics simulations, we show that two hexagonal monolayers of spherical soft colloids can self-organize in a vast array of 2D patterns exhibiting complex tessellations, provided that they are deposited onto each other in a sequential fashion. By simply tuning the relative packing density of the two monolayers we obtained not only honeycomb and rectangular lattices, but also (dis)ordered non-regular tessellations comprising of regular and non-regular convex polygons ranging from triangles to octagons. Strikingly, we could obtain hexagonal and rhomboid superlattices exhibiting unit cells comprising 3- to 8-coordinated particles. A quantitative comparison between experiments and simulations clearly shows that such patterns can emerge from simple Hertzian-like repulsive pair-potentials. Finally, we demonstrate that target colloidal tessellations can be deposited over macroscopic scales.