Simulation model for CMUT with rapid structure fluid interaction in time domain

The dynamic deflection and acoustic radiationof thin plates or membranes greatly depends on theacoustic load on top of the vibrating structure. An electroacousto-mechanical model has been built describing thesolid-fluid interaction in time domain. The model isoptimized for thin plates and membranes, and can beused for simulating CMUTs (Capacitive MicromachinedUltrasonic Transducers) in different fluids, but is also validfor any vibrating structure. The model provides accurateinformation about the sound pressure on the surface ofthe transducer, taking into account the dynamical forceindicated to the vibrating structure by the fluid. Allcalculations are done in time domain keeping the nonlinearbehavior of the transducer. Simulations results for CMUTdesigns with resonant frequencies between 5 an 40 MHzhave been compared to measurements results on devicesfabricated at Fraunhofer IPMS showing good agreement.