阀门

Abstract(#br)We present leakage-free valves and an efficient fixed-volume mixer fabricated using a four-layer soft lithography technique in polydimethylsiloxane (PDMS). Mixing is achieved with a 95% efficiency in a few seconds by creating circular flow patterns inside a simple rectangular chamber. Pressurized air is used to actuate control chambers for active valving and mixing. In our device, neither the mold nor the microfluidic channel requires complex designs.

Abstract(#br)We present a microfluidic chip for cell handling applications fabricated in polydimethylsiloxane (PDMS). The chip was designed to accumulate cells inside a reaction chamber where they can be manipulated under attendance of a liquid reagent (PEG–polyethylene glycol) for cell fusion. To enable the cell handling a fluid management system was developed which includes pneumatically actuated microfluidic valves integrated into the chip. Various valve geometries were simulated in ANSYS and characterized in a series of tests to identify a feasible valve concept.

In this paper we present various pneumatically actuated microfluidic valves to enable user-defined fluid management within a microfluidic chip. To identify a feasible valve design, certain valve concepts are simulated in ANSYS to investigate the pressure dependent opening and closing characteristics of each design. The results are verified in a series of tests. Both the microfluidic layer and the pneumatic layer are realized by means of soft-lithographic techniques. In this way, a network of channels is fabricated in photoresist as a molding master.