Micromachining a Miniaturized Capillary Electrophoresis-Based Chemical Analysis System on a Chip

TLDR

The study demonstrates principles that enable a miniaturized, no‑moving‑part system for sample handling and separation. Micromachining produced 1‑by‑2 cm glass chips that use electroosmotic pumping and electrophoretic separation, with a manifold of intersecting capillaries for sample dilution and voltage‑controlled flow direction. The etched capillaries achieved amino‑acid separations with up to 75,000 theoretical plates in about 15 s, and 600 plates in 4 s.

Abstract

Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.