Lumped Parameter Model of a Capacitive Micro-machined Ultrasound Transducer

O. Chkalov, O. Beznosyk, B. Kyriusha, O. Finogenov (Kyiv Poytech. Inst., Ukraine)

The objective of the project is to develop a model for the capacitive ultrasonic transducer described in the Ladabaum et al., [1] paper. The main element of the transducer is a metalized silicon nitride membrane suspended on a rigid support above a heavily doped silicon bulk. The cavity under the membrane is vacuumed. When a voltage is applied between the metalized membrane and the bulk, the Coulomb forces attract the membrane toward the bulk, but stress within the membrane resists the attraction. The model developed in the project is based on the lumped parameter representation of the membrane, is easy to characterize, and is suitable for small and large signal analyses.