Laser fabrication of micropores and their integration to microfluidic platforms for DNA electrophoresis

The work presents an alternative method for the manufacture of micropores by using the combination of laser ablation and wet etching. The process of laser ablation was done on silicon (Si) wafers with silicon nitride (Si₃N₄) used as a sacrificial layer. The size of the pores was carefully controlled by following an optical technique. The method exhibits a series of advantages in relation micromachining techniques previously used. The fabricated pores were then integrated to polydimethylsiloxane (PDMS) microchannels, which constitutes a novel setup to be considered for microfluidic applications. Furthermore, as the system is addressed to study the electrically-driven transport of macromolecules, deoxyribonucleic acid (DNA) electrophoresis was performed in the fabricated microsystems to prove the principle. Also for these purposes, the electric field throughout the microchannel and pore region was studied in details by using numerical simulations.