Simulation and Optimization of a Single Heater Convective PCR Chip and Its Controller for Fast Salmonella Enteritidis Detection

The design and optimization of a Rayleigh- Bénard convection based polymerase chain reaction (PCR) microchip is presented. This PCR microchip simplifies the fabrication, implementation and control of microfluidic PCR while enhancing the detection of the bacterial pathogen Salmonella Enteritidis. The device's dimensions were optimized using multiphysics simulation then it was fabricated using high precision milling of Poly(methyl methacrylate) (PMMA) substrate. The device incorporated a single heater at the bottom end of its cylindrical chamber and two sensors at both ends. The heater was controlled using a fuzzy proportional, integral, derivative (PID) controller to maintain denaturation and annealing temperatures necessary for efficient PCR to take place. Salmonella Enteritidis DNA was successfully detected using the device while reducing the required assay time by 66%.