James Norman Barshinger

Effect of Mass Damping and Stiffness Damping in Micromachined Air Coupled Capacitance Transducer

Performance of MEMS devices relies largely on the interaction between structural actuation membranes and fluids surrounding them. When optimizing these MEMS design it is importent to consider the general characteristics of this fluid‐structure interaction. Finite Element approach is used to study the effect of mass damping and stiffness damping arising due to micro fluid layers in Micro‐machined Air‐coupled Capacitance transducer. Transient dynamics of these systems are completely driven by this fluid‐structure interaction. The aim of this paper is to understand the variations in mass and stiffness damping with frequency of operation. Furthermore, the effect of the mass and stiffness damping with geometrical parameters and transient behavior of the system are discussed.

Finite Element Analysis of Capacitive Micromachined Ultrasonic Transducer (CMUT) for NDE Applications

This paper presents a comparison of three Finite Element approaches for modeling the behavior of a Capacitive Micromachined Ultrasonic Transducer (CMUT). CMUTs have become very popular over the last decade because of the comparable bandwidth, sensitivity and dynamic range with its piezoelectric counterparts. The ease of fabrication is an added advantage. Modeling of CMUTs is a coupled physics problem, which involves solving Electrostatics and Structural interactions simultaneous. Finite Element models of the CMUT are constructed using the commercial code ANSYS (9.0). Three different approaches of solving the coupled field problem are discussed and the results are compared for resonance frequency, collapse voltage, capacitance and electromechanical coupling coefficient. The approaches discussed involve sequentially coupled‐field analysis, direct coupled‐field analysis and reduced order modeling. Detailed results have been presented for the effect of variation in geometrical factors as predicted by the thre...