Dead-end injection molding of polymeric microcantilever arrays

This paper describes a novel fabrication technique for polymer-based microcantilever arrays in elastomer molds. The technique relies on the gas permeation of mold materials such as poly(dimethyl siloxane) (PDMS), which could be shown to allow dead-end filling of the mold without remaining air pockets. The PDMS master mold for the cantilever array was replicated from a photostructured SU-8 layer. A photocurable epoxy was used to produce arrays of up to 12 cantilevers (110-510 μm long, 100-200 μm wide, 12 μm thick) with spring constants ranging from 0.6 N/m to 3.0 N/m. As the PDMS master can be reused repeatedly, the technique can be adapted to mass-fabrication at sub-USS cost per device.