Photolithography

Soft photolithography is the most common method of generating a microfabricated structure for microfluidics. To do this, as shown below, a reverse mold is created by shining a UV light through a mask, which cures a photosensitive epoxy resist below it. When the uncured photoresist is washed away, this leaves a mold with which a polydimethylsiloxane (PDMS) stamp is created. PDMS can be bonded to glass or other substrates to create the channels that fluids will flow through.