Improvement in mixing efficiency of microfluidic passive mixers functionalized by microstructures created with proton beam lithography

Abstract

In this work, different microfluidic passive mixer devices were designed, simulated and realized. The mixing unit area was functionalized by microstructures, whose shapes and layouts were designed in the simulations to improve the mixing efficiency of the chips. It is known that a micro wall array is a promising tool for mixing in a microfluidic passive mixer device. In the present work, the length and the areal density of the walls in the micro wall array were varied in order to find good mixing performance. The devices were then created with ion microlithography and UV lithography techniques. Mixing test were performed from which the mixing efficiencies were determined. It was found, that the mixing efficiency of the fabricated passive micromixers can be improved to an excellent value by more densely distributed and longer micro-walls.