Modular concept of a laboratory on a chip for chemical and biochemical analysis

A novel concept of a modular micro chemical analysis system fabricated on silicon wafers using semiconductor technology is presented. The strategy was to design and to develop single fluidic components with specific functions for sample handling, manipulation and measurement. All devices presented are based on monolithic structures manufactured with the same simple microfabrication techniques. The devices are designed to handle particle containing solutions allowing novel applications in biochemical and cytochemical analysis. Components have been developed for chemical analysis such as flow switches for valve-less sample injection and flow guiding, immobilization reactors, dialysis chambers, and filters, and for cell analysis and flow cytometry such as cell sorters and coulter counters. These single fluidic components are freely combinable, which enables the design of analyzers designed for a specific application. Additionally, all fluid components can be equipped with integrated gold electrodes allowing conductivity measurements inside the microchannels. This opens up new application in chemical and biochemical analysis. A few examples in cell diagnostics such as how cytometry on a chip and in micro flow injection analysis are shown. (C) 1998 published by Elsevier Science S.A. All rights reserved.