Fabrication of micro/nano fluidic channels with sacrificial galvanic coupled metals

We report a new sacrificial method for micro/nano fluidic channel fabrication by galvanic corrosion of coupled metals. Different metal combinations and etchants are investigated for achieving a high channel etching rate with very small channel cross-sections. Channels as well as channel arrays, from 50 µm to tens of nanometres wide, are fabricated by using coupled Cr/Cu as the sacrificial layer. The channel etching rate is investigated as a function of time and width. The channel etching rate of the coupled metals is approximately 10 times faster than that of the single metal. This method is advantageous because of the high resolution, relatively high throughput, and the simplicity of the process.