The fabrication process for making PDMS microfluidic devices consists of two processes:
- Master mold photolithography
- Soft lithography
Master mold photolithography
Molds are first designed using CAD software and then converted into either a 1) chrome mask or 2) high-density printed transparency mask. The masks can then be submitted to a microfluidics foundary along with details about feature sizes to be made on a fee for service basis.
Master molds can also be fabricated in a cleanroom with photolithography equipment using this generic process.
Note: Each facility varries with the equipment and protocols. Please get trained with your facility prior to fabricating molds and use this procedure only as a general process.
PDMS soft lithography
PDMS microfluidic devices are fabricated using the soft lithography technique. In this method, PDMS is poured and cured on top of a master mold and retains features once peeled away. Detailed protocols can be found to create multilayer soft lithography PDMS devices here.
Note: Spin curves and bake times are highly dependent on the type of PDMS and equipment. This protocol may need to be adjusted to fit your materials and equipment accordinaly.