Apparatus and method for performing microfluidic manipulations for chemical analysis and sysnthesis

Abstract

A microchip laboratory system and method provide fluid manipulations for a variety of applications, including sample injection for microchip chemical separations. The microchip is fabricated using standard photolithographic procedures and chemical wet etching, with the substrate and cover plate joined using direct bonding. Capillary electrophoresis and electrochromatography are performed in channels formed in the substrate. Analytes are loaded into a four-way intersection of channels by electrokinetically pumping the analyte through the intersection, followed by switching of the potentials to force an analyte plug into the separation channel.

What is claimed is:  
     
         1 . A microfluidic device, comprising: 
 a body having disposed therein: 
 at least first, second, third and fourth channels communicating at a first channel intersection;  
 at least first, second, third, and fourth reservoirs; and  
 wherein the first channel connects the first reservoir to the first channel intersection, the second channel connects the second reservoir to the first channel intersection, the third channel connects the third reservoir to the first channel intersection, and the fourth channel connects the fourth reservoir to the first channel intersection; and  
 at least first, second, third and fourth electrodes disposed in separate electrical contact with each of the first, second, third, and fourth reservoirs, respectively, but not disposed in the channels, at least the first, second, and third electrodes simultaneously having a controlled electrical potential associated therewith.