Sub-60 nm nanofluidic channels fabricated by glass-glass bonding

A simple method is proposed to fabricate channels with a depth in the nanometer range on a borosilicate glass substrate without cost-expensive lithography. Nanochannels are constructed with bulk micromachining by BOE wet etching process. Sub-60 nm deep nanofluidic channels on chip are formed after glass-glass fusion bonding, which are confirmed by using various methods of nanometer scale measurement. The aspect ratio is down to 0.002 in our present experiments. The main advantage of the technique is the transparency of nanochannels, which allows optical fluorescence microscopy to be used for sensitive detection of nanofluidics and microfluidics.