MICROVALVES IN MICROFLUIDIC DEVICES. PART 2. PASSIVE MICROVALVES (REVIEW)

Valves are important functional elements needed to create microfluidic devices, lab-on-a-chip platforms, and micro total analysis systems (μTAS). An ideal microfluidic system integrates numerous sequential operations, provides precise spatiotemporal release of reagents and flow control, and is suitable for fast and low-cost fabrication. Therefore, the development of valves is one of the most important tasks when constructing such systems. Compared to active valves, passive valves are more convenient for integration into microfluidic devices, since they allow you to regulate the flow rate without complex feedback and provide flow shut-off, flow mixing, etc. Passive microvalves have a lower cost and simpler design than active ones. The article discusses passive check and capillary microvalves and provides examples of different designs.