Pressure-resistant and reversible on-tube-sealing for microfluidics

We present the design, manufacturing, and characterization of a novel miniaturized on-tube-seal configuration for microfluidic devices. The seal is based on a previously developed world-to-chip spring-based interface by Kortmann et al. (Lab Chip 9:1455-1460, 2009a), which enables rapid and reliable microfluidic connections. In this study, the dead volumes, the contact pressure, the discontinuous fluidic-profile transmission, and the space requirements were significantly optimized by a new on-tube-seal configuration. Maintaining the advantages of the previously described interface, the new on-tube-seal configuration has a dead volume of only 18 nl, withstands pressures higher than 2,800 kPa with only 3.8 N applied contact force, and allows continuous capillary to chip fluidic profile transmission. The on-tube-seal configuration consists of a miniaturized o-ring (0.5 x 0.3 mm) integrated into a 1/16aEuro(3) tubing that reduces space requirements to a minimal sealing grid of 1.59 mm and is easily adaptable to any planar channel opening of micro fluidic devices. In summary, we present a novel combination of gasket and tubing, which we termed on-tube-seal that allows simple, rapid, and reliable world-to-chip sealing.