Effect of design on the replication of micro/nano scale features by micro injection moulding

The replication of micro/nano scale features is of great interest for MEMS and Microsystems. However, the
flow behaviour of melts into a micro/nano cavity is still not well understood. In this work, we used the micro
injection moulding process to replicate micro/nano scale channels and ridges from a Bulk Metallic Glass (BMG)
cavity insert. High density polyethylene (HDPE) was used as the moulding material. The influence of feature
configuration, length, width, gap distance between features, location on substrate, and substrate thickness on the
quality of replication was investigated. The experiments revealed that the replication of ridges, including feature
edge, profile and filling distance, was sensitive to the flow direction; a critical feature length was found below
which the filling of features was significantly reduced. Both the feature location and the substrate thickness had an
influence on the filling of micro/nano features while the gap distance had a negligible effect on the replication of features.