title: StarTube: a tube with reduced contact line for minimized gas bubble resistance.
abstract: In this work we introduce a novel tubing design for multiphase flow that minimizes gas bubble resistance. The design termed "StarTube" has a lamella-like wall structure and was developed to prevent clogging by gas bubbles. This is performed by forcing gas bubbles into the center of the tube by capillary forces, allowing liquid to bypass in the outer grooves. It was found that the mobility of gas bubbles in such a tube is increased more than 1 order of magnitude. The reason is that the contact line perpendicular to the direction of flow is minimized, reducing resistant effects related to the contact line-in particular, contact angle hysteresis.
authors.affiliation: Laboratory for MEMS Applications, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 106, 79110 Freiburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Metz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Streule
authors.forename: Roland
authors.initials: R
authors.lastname: Zengerle
authors.forename: Peter
authors.initials: P
authors.lastname: Koltay