Micropatterning of Silica Nanoparticles by Electrospray Deposition through a Stencil Mask

This article describes the local deposition, or micropatterning, of silica nanoparticles (NPs) using an electrospray method with a stencil mask. The proposed technique can be carried out in a single step at room temperature and atmospheric pressure under dry conditions, allowing it to be used with water- or vacuum-sensitive materials, and leading to cost reductions and high throughput. An evaluation of the patterning accuracy using a 20 µm thick mask showed that for patterns with line widths greater than 50 µm, the pattern was reproduced with an accuracy greater than 95%. When silver NPs were preferably deposited on the silica NPs using a modified silver mirror reaction, they were found to exhibit strong surface-enhanced Raman scattering effects. The proposed process is readily applicable to the development of highperformance micro total analysis systems.