Molecular Foundry researchers have simulated particles that can spontaneously self-assemble into networks that form geometrical arrangements called Archimedean tilings. The key to realizing these structures is a strategy called minimal positive design, in which both the geometry and the chemical selectivity of the particles is taken into account. The process has applications in molecular self-assembly, which could one day be used to build a variety of nanoscale technologies.
Previously, researchers have successfully self-assembled particles into Platonic tilings, which are simpler arrangements consisting of regular periodic arrays of a single shape, such as squares, triangles, or hexagons. To do this, researchers use a strategy called positive design, in which the desired structure is promoted based on the particle geometry. When the particles are combined and cooled, they spontaneously self-assemble into Platonic tilings due to a variety of underlying chemical, physical, and thermodynamic interactions.
Self-assembling particles into the next-simplest arrangement, Archimedean tilings, is much more difficult. Archimedean tilings are composed of two or three different shapes, and only one type of vertex (so if you zoomed in on the intersection points, they would all look the same, having the same angles in the same order). There are eight types of Archimedean tilings, and the new design strategy can construct all eight of them.