A sacrificial SU-8 mask for direct metallization on PDMS

A new fabrication technology utilizing SU-8 as a sacrificial mask for metallization of the PDMS surface is presented. The sacrificial SU-8 layer process offers superior performance for reliable and repeatable metallization on the PDMS layer. Sacrificial SU-8 masks from 45 µm to 250 µm thickness are successfully fabricated on the PDMS layer to pattern gold on the PDMS surface. These layers are successfully peeled off from the PDMS surface after a metal deposition step. Metal lines from 10 µm to 500 µm wide and 1 mm to 50 mm long are successfully patterned and tested. Furthermore, the sacrificial SU-8 mask can be removed within minutes to realize metal patterns on the PDMS surface and does not leave any residue after removal of the SU-8 layer. As this new process is intended for use in fabrication of microfluidic and biomedical microdevices, electrodes of an electro-enzymatic glucose sensor are presented to demonstrate the technology.