High aspect ratio nano fluidic channels by laser controlled fracturing

This paper reports a novel laser processing technique for making channels in the nano regime. A Nd:YAG laser was used to dry fabricate micro channels (25 /spl mu/m-100 /spl mu/m diameter) in a 1 cm/sup 3/ fused silica substrate by thermal-induced processing. By controlling the locations of these initiating micro channels on a silica cube, 1D-controllable self-connecting nano fractures can be formed as rectangular channels. These nano channels are smooth and with extremely high aspect ratio (/spl sim/10/sup 4/ depth to width ratio). The length of the channels is controlled by the separation of the initiating micro channels. This laser-based nano channel fabrication technique is fast and inexpensive, and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.