Vacuum-driven Dry Assembly of Electrostatically Levitated Microspheres on Perforated Devices

Here, we propose a novel dry assembly method that is automatable and improves the speed, versatility, and robustness of the current methods for assembling two-dimensional (2D) arrays comprising microspheres on perforated silicon devices. The microspheres are first electrostatically levitated and instantaneously captured on the through-pores of the device by applying a vacuum force. Owing to the reversible nature of the arresting vacuum force, the 5 - 10 μm assembled silica, polystyrene, or polymethyl methacrylate (PMMA) microspheres with a pitch of 1.25 μm can be replicated on soft elastomeric surfaces. Therefore, this technique may serve as a platform for printing new materials.