Manual assembly of microcrystal monolayers on substrates

(Figure Presented) Do-it-yourself: Monolayers of molecules and nanoparticles should be prepared on substrates only by self-assembly, but monolayers of microparticles can be produced by both self-assembly and direct manual attachment as if they are tiles (see picture). The quality of the monolayers is better when they are assembled by hand than by self-assembly.