Development of separated micromold system for an efficient replication of high aspect ratio microstructures

In the present study, a separated micromold system (SMS) is newly proposed and developed for an efficient replication of high aspect ratio microstructures. The present SMS basically consists of micromold modules, each having a split structure of the complete microstructure to be replicated. So fabricated micromold modules are assembled for a replication of the microstructures and subsequently separated in a demolding stage. In this manner, serious problems commonly encountered in a conventional fabrication process for high aspect ratio structures can be effectively overcome. For a precise fabrication of the micromold modules, a deep X-ray lithography and nickel electroforming processes were carried out, resulting in nickel SMS including various half circular microstructures. By utilizing the obtained SMS modules, high aspect ratio micro-scale cilium structure and its array were successfully replicated by a hot embossing process.