Frequency-dependent transversal flow control in centrifugal microfluidics

Abstract

This work presents a novel flow switch for centrifugal microfluidic platforms which is solely controlled by the Coriolis pseudo force. This Coriolis switch consists of an inverse Y-structure with one common upstream channel and two symmetric outlets on a rotating disk. Above a certain threshold frequency, the Coriolis force becomes dominant that the entire flow is diverted into one of the outlets which is selected by the direction of rotation. The threshold frequency has been measured to be 350 rad s⁻¹ (∼55.7 Hz) for a channel width of 360 µm and a depth of 125 µm. The results are supported by extensive CFD simulations.