Direct fabrication of a microfluidic chip for electrophoresis analysis by water-assisted femtosecond laser writing in porous glass

We report the direct fabrication of a microfluidic chip composed of two high-aspect ratio microfluidic channels with lengths of 3.5 cm and 8 mm in a glass substrate by femtosecond laser micromachining. The fabrication mainly consists of two steps: 1) writing microchannels and microchambers in a porous glass by scanning a tightly focused laser beam; 2) high-temperature annealing of the glass sample to collapse all the nanopores in the glass. Migration of derivatized amino acids is observed in the microfluidic channel by applying electric voltage across the long-migration microchannel.