Interconnected multi-level microfluidic channels fabricated using low temperature bonding of SU-8 and multilayer lithography

摘要

This paper describes a novel fabrication method for the manufacture of multi-levelrnmicrofluidic structures using SU-8. The fabrication method is based on wafer bonding of SU-8rnlayers and multilayer lithography in SU-8 to form microchannels and other structures at differentrnlevels. In our method, non-UV-exposed SU-8 layers are transferred to SU-8 structured wafers atrndesirably low temperatures. This technique is particularly useful for building multi-level fluidicrnstructures, because non-UV-exposed SU-8 can be used as cover for microchannels and the coverrncan then be lithographically structured, i.e., to form interconnects, after which subsequentrntransferring of non-UV-exposed SU-8 onto the wafer allows for the fabrication of interconnectedrnmulti-level channels and other structures. Examples of interconnected multi-level microchannelsrnwere realized using this newly developed method. Liquid has been introduced into thernmicrochannels at different levels to reveal the desirable functionality of the interconnected multilevelrnchannels. The method described here is easily implementable using standardrnphotolithography and requires no expensive bonding equipment. More importantly, thernfabrication procedure is CMOS compatible, offering the potential to integrate electronic devicesrnand MEMS sensors into microfluidic systems.