Novel Compact Model for Rapid Design Optimization of CMOS-compatible Micro-PCR chips for COVID-19 Detection

For the first time, an NL PDE (nonlinear partial differential equation)-based compact model to predict the transient thermal behavior of a CMOS-compatible micro PCR (polymerase chain reaction) chip is proposed for rapid device optimization. The model is first validated using experimental data with an average error of 0.4% and then employed to explore the effect of crucial parameters on micro PCR design. According to the parametric scaling analysis, two critical factors - the thickness and the width of micro PCR heaters - show dominant impacts on the performance, including power efficiency, heating rate, and cooling rate. Due to the low computational cost of our compact model, design optimization can be conducted within 10 seconds, approximately 170 times faster than that with typical FEM simulation. After the effective optimization, the heating rate $(Q_{h})$ and cooling rate $(Q_{c})$ improved to $6.347^{\circ}\mathrm{C}/\mathrm{s}$ and 2.159 $^{\circ}\mathrm{C}/\mathrm{s}$, resulting in a significant increase of 799.47% and 166.23%, respectively, compared to the initial design under the identical working conditions. In conclusion, the validated compact model will be promising to be used for next-gen CMOS micro PCR devices using TSMC $0.18\mu\mathrm{m}$ CMOS/CMOS MEMS foundry processes for COVID-19 detection.