Laser induced damage in porous glass - a pathway to 3D fabrication of micro-/nanofluidics

We report on controllable production of nanostructures embedded in a porous glass by femtosecond laser direct writing. We show that a hollow nano-void with a lateral size of similar to 40 nm and an axial size of similar to 1500 nm can be achieved by manipulating the peak intensity and polarization of the writing laser beam. The single nano-voids can be smoothly connected into a continuous nanochannel by water-assisted femtosecond laser direct writing. With this technique, integrated micro-nanofluidic systems have been achieved by simultaneously writing micro- and nanofluidic channels arranged into various 3D configurations in glass substrates. The fabricated micro- and nanofluidic systems have been applied to demonstrate DNA analysis, e. g., stretching of DNA molecules. Our technique offers new opportunities to develop novel 3D micro-nanofluidic systems for a variety of lab-on-a-chip applications