Testing of pneumatic actuation micro valve module for lab-on-a-chip application

Abstract

Pneumatic actuation type valves have been used successfully applied in many lab-on-chip applications because of their low cost, simple fabrication techniques, and easy to operate. Overall, micro valves module consisted of thermoplastic polyurethane (TPU) film that sandwiched with elastomer silicone layers. TPU films itself is already available in the market and toxic-free whenever contacted with sensitive organic material. The film acted as a diaphragm that pneumatically actuated the valve to be open in a control chamber. In this work, we designed and simulated the valve module to allow fluid flow by applying vacuum pressure on the film at the control chamber. Our study showed that by using a vacuum pressure at -1,467 Pa, the TPU film shall be deflected at a maximum distance of 1.6 mm. This gap resulted in a flow rate of liquid at a rate of 1-5 mL/hr. We also demonstrated that the fabrication of the complete module was relatively easy since using basic mold transfer technique. The performance of the valve was confirmed by measuring the flow rate and liquid before and enter the valve actuation point. It showed that the margin was less than 3% by comparing flow that entered and left the valve chamber.