Planar thin film device for capillary electrophoresis

Abstract

Hollow tubular microfluidic channels were fabricated on quartz substrates using sacrificial layer, planar micromachining processes. The channels were created using a bottom-up fabrication technique, namely patterning a photoresist/aluminum sacrificial layer and depositing SiO₂ over the substrate. The photoresist/aluminum layer was removed by etching first with HCl/HNO₃, followed by etching in Nano-Strip, a more stable form of piranha (H₂SO₄/H₂O₂) stripper. Rapid separation of fluorescently labeled amino acids was performed on a device made with these channels. The fabrication process presented here provides unique control over channel composition and geometry. Future work should allow the fabrication of highly complex and precise devices with integrated analytical capabilities essential for the development of micro-total analysis systems.