Flexible microfluidic circuit with embedded in-plane valve.

摘要

Recent developments in Microfluidic systems have demonstrated many potential applications related to biology, chemistry and medical sciences. Fluidic manipulation with precise volume control is a basic function in these systems, and microvalves play an important role in control and delivery of the fluid sample. One of the key issues in such valve design is to make large membrane deflections compared to the channel dimension. This thesis reports a flexible microfluidic chip with embedded in-plane valves for fluid manipulation. Silicone elastomer (Polydimethylsiloxane - PDMS) is one of the most suitable materials to fabricate microvalve membranes, because of its low Young's modulus, excellent sealing property and rapid prototyping procedures. The proposed in-plane control valve utilizes pneumatic pressure source to squeeze the channel and restrict the flow through channel. These in-plane valves can be fabricated in a single layer with a plane top covering layer, hence reduces the multiple layers and alignment issues related to layer stacking. The experimental results show a membrane deflection of 25mum with an applied pressure of 70psi. The prototype valves have a leakage ratio ranging between 0.4 and 0.2. These valves can be used for transportation of continuous and discrete volume flow.