Design and Fabrication of a Centrifugal Microfluidic platform for Efficient Mixing and Whole Sample Collection Using Pneumatic Force

Centrifugal microfluidic or lab-on-a-disc (LoaD) platforms are emerging technology which have many advantages over other microfluidic systems and could be potentially used in clinical and extreme point-of-care settings. Mixing and flow control of samples play a pivotal role in sample preparation step for many bioassays. We designed a new centrifugal microfluidic configuration which combined a pneumatic reciprocating mixer and siphon valve. Siphon valves employ temporary storage and subsequent release of pneumatic energy, only controlled by rotation of the disk and without the need of surface treatment. Using pneumatic energy in a passive form for mixing reagents is a brilliant concept due to its easy implementation and high efficiency. Also we applied a more efficient disc fabrication technique by using alternative approach to conventional ones. Here, instead of using computer numerical control (CNC) a laser cutter was implemented to create larger elements like chambers on the disc and the microchannels were only cut on the pressure sensitive adhesive (PSA). The developed LoaD was characterized using image processing and the results showed that the proposed configuration is suitable for both mixing and transferring the whole processed sample to a collection chamber for further analysis.

Keywords:

Centrifugal microfluidics , Pneumatic mixing , Pneumatic siphon valve