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 -40 nm and an axial size of -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.