Rapid fabrication of poly(dimethylsiloxane)-based microchip capillary electrophoresis devices using CO2laser ablation

Abstract

The use of CO₂ laser ablation for the patterning of capillary electrophoresis (CE) microchannels in poly(dimethylsiloxane) (PDMS) is described. Low-cost polymer devices were produced using a relatively inexpensive CO₂ laser system that facilitated rapid patterning and ablation of microchannels. Device designs were created using a commercially available software package. The effects of PDMS thickness, laser focusing, power, and speed on the resulting channel dimensions were investigated. Using optimized settings, the smallest channels that could be produced averaged 33 µm in depth (11.1% RSD, N = 6) and 110 µm in width (5.7% RSD, N = 6). The use of a PDMS substrate allowed reversible sealing of microchip components at room temperature without the need for cleanroom facilities. Using a layer of pre-cured polymer, devices were designed, ablated, and assembled within minutes. The final devices were used for microchip CE separation and detection of the fluorescently labeled neurotransmitters aspartate and glutamate.