Design, modelling and FEM-based validation of composite membrane circular cMUT cell

The paper presents an analytical model for the design of a composite membrane circular capacitive micromachined ultrasonic transducers (cMUT) cell. The analytical model harnesses composite membrane layer cMUT cell based on the mass-spring-damper system. The effects of damping due to the surrounding medium and acoustic impedance of self-radiation as well as identical neighbouring cells cluster are also modelled for dynamic analysis of unit cMUT cell. The validation of analytically obtained results is performed through FEM simulations using MEMSCAD tool CoventorWare^®. The analytically obtained results show good agreement with the FEM simulation results. The designed structure is based on the wafer bonding technology, which is well established at the authors’ laboratory. It is a low temperature anodic bonding process without through silicon via/through glass via (TSV/TGV) technique requirement (Aditi et al. in IEEE 24th Electronics Packaging Technology Conference (EPTC), 2022). Composite membrane circular cMUT cell is designed and validated for air-coupled application; moreover, the model developed is also applicable to other fluids as well.