Hierarchical wrinkle structuring on inside wall of closed micro channel

This paper presents a surface structuring method for a closed micro channel. Because fine photolithography can only be made on a flat surface, it has been difficult to make complicated patterns on the inside walls of non-planar microfluidic channels. Here, we demonstrated that micro-scale hierarchical patterns can be formed on the inside walls of the micro channel simply by depositing a plastic thin film in the channel and stretching the micro channel.