Microfluidic Modules with Integrated Solid-State Sensors for Reconfigurable Miniaturized Analysis Systems

Abstract

The fast and simple fabrication of modular microfluidic devices comprising different fluidic components and configurations that can rapidly be assembled and reconfigured depending on the requirements of a particular application is very attractive. The application of these modular systems as complete analysis systems requires the incorporation of flow-cell modules capable of selectively detecting chemical species. Here, a new magnetic clamping approach is presented that allows both interconnection of microfluidic modules and reversible integration of solid-state sensors. Planar and optically transparent materials are used to easily assess device fluidic performance. Double-sided polyacrylic adhesive layers, sandwiched between two transparent polycarbonate films, are mechanized to produce fluidic structures containing the required inlets and outlets. The latter also include chemically bonded poly(dimethylsiloxane) gaskets for easy leak-free interconnection of the different modules and the incorporation of chemical sensors without adding dead volumes. Microfluidic channels, junctions, mixers and flow cells with solid-stated sensors are thus fabricated. Different microfluidic modules are assembled with the aid of poly(methyl methacrylate) clamping structures containing embedded magnets. By using a magnetic breadboard, complete microfluidic analysis systems can be arranged in a few minutes. Three systems incorporating conductivity, amperometric, or pH sensors are thus assembled and fully characterized to show the advantages of the presented approach for analytical applications.