3D diffuser lithography: a novel method to fabricate various rounded microstructures

In this work, we developed a novel method to fabricate various rounded microstructures by using simply a diffuser in the conventional lithography step (so-called 3D diffuser lithography). Using this method, we demonstrated circular as well as elliptical microstructures in a thick photoresist and PDMS microlens arrays. Furthermore, we obtained the high-density photoresist patterns formed by simply decreasing the spacing between the photoresist patterns, which was used for the high fill-factor microlens array. Also, various possible MEMS applications with rounded microstructures such as microswitches and microshutters were proposed.