Microfilm-Formation of High-Viscosity Liquids by Blade Shear Coating

The distribution of high-viscosity microfilms in designated regions is crucial for the performance and durability of MEMS devices. This paper presents a novel method for controllable film formation in the milli/micron region by blade coating. A microfilm can be formed without viscosity limitation, and the formation process can be monitored only via a one-dimensional force sensor. The dynamics of the blade-coating process are analyzed in detail. The experimental results indicate that the initial height of the blade gap is the determining factor of film thickness, whereas the film length can be adjusted individually by the scratching speed without influence on film thickness. Moreover, the tangential force varies obviously in different coating parameters while exhibiting a similar trend.