Investigating the technological limits of micro-injection molding in replicating high aspect ratio micro-structured surfaces

Micro injection molding is a key technology for mass-production of micro-structured surfaces, such as optical and microfluidic devices. However, the complete replication of high aspect ratio micro features is challenging even using state-of-the-art high-speed injection systems, rapid heat cycle molding and vacuum mold venting. In this work the technological limits of micro-injection molding in replicating high aspect ratio micro-structured surfaces are experimentally investigated, using the molding of a bio-MEMS for erythrocytes depletion as a case study. The obtained results show how these limits are inherently related to an uneven distribution of cavity pressure during mold filling. (C) 2014 CIRP.