Self-assembly of fine particle on three dimensional curved structure

Abstract

Assembly of fine particles on three dimensional curved structure enables a lot of applications such as biochemical sensors. Dip coating method is often used because of its high productivity, but this method has been applied only to planar substrates. The spreading shape of suspension on the three dimensional curved structure is different from the planer substrate and changes the assembly process mechanism. This paper aims to assemble particles on a three dimensional curved structure of which shape continuously changes by extending the assembly model for planar substrate. When the drawing speed from the suspension that contains particles is constant, the recession speed of the contact line changes depending on location of the curved structure. Spreading shape and recession speed with 5 mm quartz cylinder has been investigated based on microscopic observation. The effects of cylinder diameter and contact angle on the recession speed analyzed with finite element method. From the results, we modeled the relationship between the drawing speed and the recession speed. The effect of the recession speed on the self-assembly of 500 nm silica particle was investigated analyzing the particle coverage for verification. The assembly model of planer substrate was extended to three-dimensional curved one. Finally, we applied the model to the assembly on a convex lens.