Design, Integration and Testing of Fluidic Dispensing Control Valve into a DNA/RNA Sample Preparation Micro fluidic Package for Lab on a Chip (LOC) Applications

A bio-microfluidic package has been developed with integrated reservoir and valves for DNA (deoxyribonucleic acid) lab on a chip (LOC) application. A polymer material, PDMS (polydimethylsiloxane) is used for encapsulating the DNA chip. Channels, reservoirs and valves are formed on the PDMS material by casting method. A double sided adhesive tape is used to bond PDMS substrates and DNA chip. A conical shape reservoir is designed to have minimum dead volume in the reservoir. Filled reservoirs with reagents are sealed by a highly elastic thin rubber membrane. An external actuation is used to apply pressure on the thin rubber membrane to push the fluid from the reservoir to the chip and to output collector. Extraction of DNA/RNA follows a protocol and is defined by a flow rate. A pin valve is designed and inserted inside the reservoir to control the fluid flow. The external actuation pushes the fluid through the pin valve and the fluid flow is proportional to the actuation speed. The actuation speed is calibrated with different flow rate and found to have a linear relation. The cartridge is successfully tested for extraction of DNA from human blood.