Fast Calculation Method for Capacitance of Multilayer-Structured Interdigital Electrode Capacitor (IDC)

The electric field and capacitance in multilayer interdigitated electrode (IDC) sensors are crucial factors for structure design, performance evaluation, and parameter optimization. This paper proposes a mathematical model based on variable separation technique to calculate the electric field and capacitance of multilayer IDC structures. The semi-analytical mathematical formulations for electrostatic field distribution and capacitive parameters, incorporating stratified dielectric media with heterogeneous dielectric constants, are developed into an infinite series expansion. The model proposed in this paper successfully generates accurate capacitance values that closely match the simulation data. Besides, the numerical computation based on the model is dozens of times faster than that using finite element method (FEM), highlighting its potential to efficiently guide IDC sensor design and optimization for exact sensing.