Robust microdevice manufacturing by direct lithography and adhesive-free bonding of off-stoichiometry thiol-ene-epoxy (OSTE+) polymer

We here demonstrate, for the first time, the use of direct lithography in off-stoichiometry thiol-ene-epoxy (OSTE+) to fabricate a microdevice. First, the photolithographic property of OSTE+ is shown by using a photomask to create micropillars with an aspect-ratio of 1:10 in a 2 mm thick layer. Secondly, a three-layer OSTE+ microdevice containing in-/outlet holes, channels, and pillars is fabricated by using a combination of direct lithography and adhesive-free dry bonding. The resulting microdevice shows desirable properties, such as leak-free filling and hydrophilic surfaces. This fabrication method enhances the microstructurability of OSTE+ beyond that of conventional soft lithography replica molding of other polymers, such as PDMS.