Design of an innovative Polymerase Chain Reaction device based on buoyancy driven flow.

Polymerase Chain Reaction (PCR) plays a central role in the field of molecular biology. The miniaturization of PCR systems is promising as it potentially minimizes costly reagent consumption and time required for analysis. In PCR microdevices a sample solution is usually handled by external pumps. An alternative solution relies on temperature-induced density difference in the presence of a body force to induce buoyancy driven flow. This alternative method is easy to be used and does not require expensive setup, but, to date, the thermo-fluid-dynamic field in the micro-channels still needs to be optimized. The present study focuses on the design of micro-channels, having innovative and optimized shapes to obtain proper fluid actuation and DNA sample amplification within buoyancy driven flow PCR devices. A parametric study is carried out by means of computational thermal fluid dynamic modeling: several channel geometry configurations were compared in terms of time required for analysis, temperature distribution and priming volume. The advantages and disadvantages of such configurations are discussed.