Lumped Element Model for CMUTs­Based Biochemical Resonant Sensor

Lumped element model (LEM) for resonant chemical sensors based on the capacitive micromachined ultrasonic transducers (CMUTs) was developed and analyzed with electrical characterization. The CMUTs chip were functionalized with the electrospinning technology. Two Butterworth Van-Dyke (BvD) models for functionalized CMUTs were proposed and analyzed with different DC voltages. Considering the electrical phase with parasitic capacitance, the modified BvD model can be used to illustrate more comprehensive features for both mechanical impedance and phase properties. The parallel capacitance was measured accurately using an impedance analyzer, and the quality factor was calculated based on the proposed model under different DC voltages. These models will provide important theoretical basis for CMUTs-based chemical sensors to further electrical analysis and oscillator design.