Fabrication of on-chip nanofluidic channels by using sacrificial photoresist ternplated SiO2 sputter deposition

Abstract

We report on the fabrication of on-chip nanofluidic channels by using sacrificial resist templates and on measurements of ionic current transport through the nanochannels. The fabrication method does not require glass fusion and uses an optically patterned resist as a sacrificial template for the nanochannels and sputtered SiO2 as the channel walls. By diluting the optical resist, we are able to fabricate fluidic channels with controlled channel dimensions ranging from 1 mu m down to 50 nm in height and 1 mm to 5 mu m in width. The ionic current measurement shows that at low NaCl concentrations (<= 0.01 mM), the conductance is dominated by surface charge conduction, which may be due to accumulated ionic charge within the charge double layer at the surface exceeding that of the bulk fluid.