Liquid reagent storage and release for centrifugally operated Lab-on-a-Chip systems based on a burstable seal

We present a new approach for the pre-storage and release of liquid reagents in centrifugally operated Lab-on-a-Chip (LoaC) cartridges. Liquids are stored in sealed cavities which are separated from the fluidic system by a weak-bonded interface. During centrifugal rotation, the liquid exerts an inertial force onto the predetermined area. This delaminates the sealing foil locally, resulting in a fluidic connection to the downstream channel. Time-to-release could be adjusted to a range between 31 s and 143 s by geometrical variations of the structure, enabling time controlled release. In sum, the burstable seal is a universal and robust valve: it is vapor tight, independent on wetting properties of liquids, and time controllable. Hence it excels siphon based valving concepts often used in centrifugal microfluidics and is most valuable for the design of LoaC cartridges for point of care applications.