The continuous emerging of microfluidic compact disc (CD) platforms for various real-life applications motivates researchers to explore new innovative ideas towards more integrated active functions. However, microfluidic CDs have some drawbacks, including the unidirectional flow that limits the usable space for multi-stepped biological and chemical assays. In this work, a novel active and bidirectional centrifugal pump is developed and integrated on microfluidic CDs. The design of the developed pump partially replicates the designs of the conventional centrifugal pumps with a modification in the connecting channels' positions that allow the developed pump to be reversible. The main advantage of the proposed centrifugal pump is that the pumping speed can be accurately controlled during spinning or while the microfluidic CD is stationary. Performance tests show that the pumping speed can reach up to 164.93 mm3/s at a pump rotational speed (impellers speed) of 4288 rpm. At that speed, 1 mL of water could be pumped in 6.06 s. To present a few of the potential applications of the centrifugal pump, flow reciprocation, bidirectional pumping, and flow switching were performed and evaluated. Results show that the developed centrifugal pump can pump 1096 µL of liquid towards the CD center at 87% pumping efficiency while spinning the microfluidic CD at 250 rpm. This novel centrifugal pump can significantly widen the range of the applicability of microfluidic CDs in advanced chemical processes and biological assays.
Keywords: centrifugal pumps; lab-on-disc; micro pumping; microfluidics.