MICROFLUIDIC CIRCUIT DESIGNS FOR PERFORMING ELECTROKINETIC MANIPULATIONS THAT REDUCE THE NUMBER OF VOLTAGE SOURCES AND FLUID RESERVOIRS

摘要

A microfabricated device and method for proportioning and mixing electokinetically manipulated biological or chemical materials is disclosed. The microfabricated device (5) mixes a plurality of materials in volumetric proportions controlled by the electrical resistances of tributary reagent channels (31a, 31b, 33a, 33b, 35a, 35b, 37a, 37b, 38a, 38b, 39a, 39b) throug h which the materials are transported. The microchip (5) includes two or more tributary reagent channels combining at one or more junctions (41, 42, 43, 4 4, 45) to form one or more mixing channels (36a, 36b, 36c, 36d, 36e). By varyin g the geometries of the channels (length, cross section, etc.), a plurality of reagent materials can be mixed at a junction such that the proportions of th e reagent materials in the mixing channel depend on a ratio of the channel geometries and material properties. Such an approach facilitates voltage division on the microchip without relying on external wiring schemes and voltage division techniques external to the microchip. Microchannel designs that provide the necessary voltage division to accomplish electrokinetic valving operations using a single voltage source and a switch are also described. In addition, microchannel designs that accomplish fluidic operati on utilizing a minimal number of fluidic reservoirs are disclosed.