The applications of integrated microfluidic chips on automatic diagnosis systems

The present study reports an integrated microfluidic chip for automatic diagnosis applications. A new "S-shape" micromachine-based pneumatic pump using the concept of the time delay of the compressed air flow is adopted to transport a minute amount of samples/reagents and automate the diagnosis process. While compared to traditional pneumatic micropumps, the new S-shape micropumps provide a higher pumping rate, and more importantly, simplify the control system. The new micromachine-based pneumatic valves and pumps formed by PDMS membranes are designed and fabricated using MEMS (micro-electro-mechanical-systems) technology and are integrated to form an automatic bio-sensing chip for fast diagnosis of the infectious diseases. Experimental data show that the driving frequency, the quantity of the intersections, and the length of the S-shape microchannel could affect the pumping rate. The bio-sensing chips integrated with the micro-pneumatic valves and the S-shape pumps could successfully execute ELISA (Enzyme-linked immunosorbent assay)-based tests using less amounts of samples and reagents within a shorter time period. The development of the automatic bio-sensing chips could provide a useful tool for fast disease detection and be crucial for a micro-total-analysis system