A Novel Magnetic Active Valve for Lab-on-CD Technology

We present a novel magnetic valving technology designed for lab-on-compact disc (CD) platforms. The working principle is based on a movable plug that, under the effect of the centrifugal force, can close off a channel. The channel can be reopened using magnetic force acting on the plug to lift off the plug from the valve seat. Different geometries and materials for the valve have been compared to optimize the manufacturability, closing (sealing), and opening properties of the valve. Among several materials tested as a valve seat, polydimethylsiloxane was found to be the best choice. Characterization and theoretical analysis of the implemented magnetic valve show that it can be efficiently used as an on-off active valve for a wide range of rotational frequencies. A theoretical model for description of the sealing properties of the valve was proposed and experimentally validated.