Multi-factor coupled thermal simulation of flat-panel digital PCR structure

To achieve uniform reaction temperature in flat-plate digital polymerase chain reaction (dPCR), we propose a multi-factor coupled thermal simulation method for the structure of flat-plate digital PCR using finite element analysis. This will help us obtain the optimal method for the structure of flat-plate dPCR. Thermal simulations were conducted to analyze the effects of forced air cooling, thermoelectric cooler (TEC) arrangement spacing, and heat-conducting plate thickness on the temperature uniformity of the flat-plate dPCR. The resulting isothermal surfaces and velocity magnitude vectors were used to summarize the impact of each factor. The study found that maintaining a mechanical fan speed of 3000 revolutions per minute (RPM) ±10 % during the heating period resulted in a 29.3 % reduction in the standard deviation of the temperature on the surface of the heat-conducting plate. Additionally, when the TEC spacing was between 2 mm and 3.5 mm, the standard deviation of the temperature on the plate's surface decreased by 87.1 % to 93.4 %. When the thickness of the thermal plate ranges from 3.5 mm to 4.5 mm, the standard deviation of the temperature on the surface of the thermal plate varies by approximately 0.006. The experimental results, obtained by sampling and analyzing the temperature on the surface of the thermal plate, are consistent with the simulation results. This proves that the method is informative in determining the structural parameters of the dPCR to enhance temperature uniformity.