Vacuum-driven assembly of electrostatically levitated microspheres on perforated surfaces

At the onset of a miniaturized device era, several promising methods, primarily wet have been developed to attain large-scale assemblies microparticles. To improve speed, versatility and robustness current methods for structured assembly microparticles, an automatable method capable forming 2D arrays microspheres on large silicon surfaces is devised. The uses perforated with vacuum-suction holes, aspiring holding individual particles from particle cloud generated by subjecting lump chargeable particles, e.g., silica, polystyrene, polymethyl methacrylate (PMMA), strong electrical field under ambient air conditions. microsphere levitation depends conductivity permittivity particles. A single or double brush stroke can remove excess covering formed arrays. We find that silica polystyrene diameter 5 μm 10 be assembled order few seconds, independently array size. Owing reversible nature arresting vacuum force, layers transferred another surface, such as polydimethylsiloxane (PDMS) sheets, thus providing key step future printing processes fabrication hierarchical materials, photonic crystals.