Development of a PDMS removable enclosure for microchannels using ultra-thick SU-8 process on silicon and glass substrates

In this thesis, the design, fabrication, and testing results of a flexible enclosure for sealing microfluidic systems are presented. Unlike conventional fluidic sealing methods, this enclosure seals microfluidic channels without using any adhesives or substrate bonding, yet remains liquid tight. Thus, cell and biological samples can be culturedin uncovered microchannels, promoting medium and waste exchange, yet sealed for flow testing. Using a newly developed process, channels were fabricated on silicon and glass substrates with 1mm high ridges and 300 μm grooves using SU-8 photopolymer. These geometric features fasten the flexible PDMS enclosure by aligning it to seal the top of the microchannel. Flow simulation using Comsol was conducted for each channel width. A syringe pump was connected to the chip, and water flow rate and pressure were monitored until leakage occurred. Finally, cells were introduced into channels for 24 hour culturing to demonstrate cell viability in the system environment.