Burst valves for commercial microfluidics: a critical analysis

Modern single-use microfluidic devices allow for affordable analysis of liquid, while remaining robust, easy-to-use and portable. Reliable and simple valving is crucial for fluid manipulation in these devices. Passive valves such as geometry-based burst valves are a frequent choice, allowing for instrumentation-free low-complexity valving. However, transfer from prototyping to manufacturing or implementation of changes in the manufacturing process oftentimes severely affect burst valve performance as material choice and surface topography impact the delicate balance of surface tension and liquid pressure in a channel. We, therefore, started this work with the goal of analyzing the influence of manufacturing techniques and materials on burst valve behavior. Yet, we soon came to learn about limitations of geometry-based burst valves when employed for commercially manufactured disposable microfluidic systems. Thence, this work presents an analytical prediction of burst valve pressure, compares predicted and experimental burst pressures based on common prototyping and manufacturing means and materials, and specifically analyses limitations of burst valves for commercial microfluidic devices. Factors influencing burst valve behavior are discussed and recommendations for robust implementation of burst valves are made.