Fabrication of Microfluidic Chips by an Ultrasonic Micromachining With Wet-Etch Smoothing Method on Glass Substrates

An ultrasonic micromachining with wet-etch smoothing process is demonstrated in this work to fabricate microfluidic chips on glass substrates. Microstructures of high aspect ratios including microchannels, microchambers and microholes were fabricated in glass substrates within a few minutes. A thin sellotape film and a sacrificing glass sheet were attached on the sample surfaces, preventing the surface scratches and cracks at the exits of the through holes. The surface morphology of the microstructures was improved by a smoothing process of ultrasonic-assisted chemical etching using the hydrofluoric (HF) acid solutions. Using this method, microfluidic chips for capillary electrophoresis (CE) and solo-chamber chips were fabricated.