| This work describes a technique for forming nanometer-scale pixilated lipid domains that are self-organized into geometric patterns residing on a square lattice. In this process, a lipid multibilayer stack is deposited onto a silicon substrate patterned with a square lattice array of hemisphere-like bumps formed by electron beam lithography. Domain patterns are shown to be confined to the flat grid between the bumps and comprised of connected and individual domain pixels. Analysis of lattices of varying sizes shows that domain pattern formation is driven by mechanical energy minimization and packing constraints. We demonstrate single lattice sizes and a gradient in lattice size varying from the micrometer to the 100 nm scale applicable to precise arraying, patterning, and transport of biomolecules that partition to lipid domains. We show that the Lo phase exists transiently, in the form of a lipid domain pixelation pattern, on the curvature-patterned sections of the substrate. In addition, we demonstrate other variations on the underlying lattice pattern that change the metastability dynamics of the pixilation pattern. This work stands as a stepping stone toward a deeper understanding of biological membranes. The well-defined nature of the domain patterns provide proof-of-concept that curvature patterning of substrates can be used to direct bending and line energy to attain cell-like dynamics. |
