Design and Analysis of Capacitive Micromachined Ultrasonic Transducer

2019 ◽  
Vol 13 (2) ◽  
pp. 108-116
Author(s):  
Rashmi Sharma ◽  
Rekha Agarwal ◽  
Ashwani Kumar Dubey ◽  
Anil Arora
Keyword(s):  
Thin Plate ◽  
Plate Theory ◽  
Ultrasonic Transducer ◽  
Fem Simulation ◽  
Simulation Software ◽  
Thin Plate Theory ◽  
Capacitive Micromachined Ultrasonic Transducer ◽  
Different Shapes ◽  
Dc Bias ◽  
Micromechanical Systems

Background:Objective:To simulate a Micromechanical systems (MEMS) based CMUT working as a transmitter with the existing design and provide comparison within the possible architectural geometries.Methods:FEM simulation software COMSOL is used to simulate the 3D model of the transducer radiating in the air. The classical thin-plate theory is employed to solve for CMUT with a circular shape which is sufficient when the ratio of the diameter to thickness of the plate is very large, an aspect common in CMUTs. The Galerkin-weighted residual technique is used to get a solution for thin plate equation with the presumption that the deflections are small in comparison to the thickness of the plate.Results:The resonant frequency of CMUT with different geometries have been calculated. The deflection of membrane with applied DC bias is shown along with collapse voltage calculation. The generated ultrasound is shown with the AC bias superimposed on the DC bias. The capacitance change with the increasing DC voltage is discussed. The deflection of membrane is maximum as the resonance frequency is proved.Conclusion:The review of Capacitive Micromachined Ultrasonic Transducer architectures with different shapes is highlighted. The working behavior of CMUT with suitable dimension is simulated in 3D providing researcher data to wisely choose the CMUT prior to the fabrication. The CMUT is prioritized on various characteristics like wafer area utilization, deflection percentage within the cavity and durability of the transducer.

scholarly journals Semi-analytical static analysis of nonlocal strain gradient laminated composite nanoplates in hygrothermal environment

2021 ◽  
Vol 43 (5) ◽  
Author(s):  
Giovanni Tocci Monaco ◽  
Nicholas Fantuzzi ◽  
Francesco Fabbrocino ◽  
Raimondo Luciano
Keyword(s):  
Thin Plate ◽  
Strain Gradient ◽  
Plate Theory ◽  
Laminated Composite ◽  
Equilibrium Equations ◽  
Thin Plate Theory ◽  
Bending Behavior ◽  
Hygrothermal Environment ◽  
Load Types ◽  
Novel Applications

AbstractIn this work, the bending behavior of nanoplates subjected to both sinusoidal and uniform loads in hygrothermal environment is investigated. The present plate theory is based on the classical laminated thin plate theory with strain gradient effect to take into account the nonlocality present in the nanostructures. The equilibrium equations have been carried out by using the principle of virtual works and a system of partial differential equations of the sixth order has been carried out, in contrast to the classical thin plate theory system of the fourth order. The solution has been obtained using a trigonometric expansion (e.g., Navier method) which is applicable to simply supported boundary conditions and limited lamination schemes. The solution is exact for sinusoidal loads; nevertheless, convergence has to be proved for other load types such as the uniform one. Both the effect of the hygrothermal loads and lamination schemes (cross-ply and angle-ply nanoplates) on the bending behavior of thin nanoplates are studied. Results are reported in dimensionless form and validity of the present methodology has been proven, when possible, by comparing the results to the ones from the literature (available only for cross-ply laminates). Novel applications are shown both for cross- and angle-ply laminated which can be considered for further developments in the same topic.

Normal Loading on a Wedge-Shaped Plate

1955 ◽  
Vol 6 (3) ◽  
pp. 196-204 ◽  
Author(s):  
D. E. R. Godfrey
Keyword(s):  
Thin Plate ◽  
Mellin Transform ◽  
Plate Theory ◽  
Normal Loading ◽  
Thin Plate Theory

SummaryThe equations of thin plate theory are expressed in polar co-ordinates and transformed using the Mellin transform. Problems involving discontinuous and isolated normal loadings may then be solved in the case of the built-in or freely supported wedge-shaped boundary.

Finite Element Modelling of Air-Coupled Circular Capacitive Micromachined Ultrasonic Transducer for Anodic Bonding Process using SOI Wafer

2021 ◽  
Author(s):  
Gurpreet Singh Gill ◽  
Sanjay Kumar ◽  
Ravindra Mukhiya ◽  
Vinod Kumar Khanna
Keyword(s):  
Finite Element ◽  
Resonance Frequency ◽  
Glass Substrate ◽  
Ultrasonic Transducer ◽  
Fem Simulation ◽  
Silicon On Insulator ◽  
Anodic Bonding ◽  
Free Standing ◽  
Design Flexibility ◽  
Capacitive Micromachined Ultrasonic Transducer

Abstract Capacitive Micromachined Ultrasonic Transducer (CMUT) provides an alternative to commercial piezoelectric-based ultrasonic transducers due to its wide bandwidth, improved efficiency, sensitivity, and design flexibility [1, 2]. In this paper, Finite Element Method-based design and simulations of circular capacitive micromachined ultrasonic transducer (CMUT) is presented. The FEM simulation of air-coupled CMUT was accomplished by using MEMCAD tools CoventorWare® and COMSOL™. The resonance frequency of 3.9 MHz was achieved for the designed circular CMUT device. A favourable agreement was found for the resonance frequency and pull-in voltage of the device using MEMSCAD tools and analytical calculations. For the proposed CMUT design, a circular cavity will be formed inside the glass substrate. Then, a free-standing membrane will be released using active layer of silicon-on-insulator (SOI) wafer. The bulk silicon of SOI wafer will be removed after bonding it on the glass substrate using anodic bonding technique as described in fabrication process flow for CMUT.

NODAL INTEGRATION THIN PLATE FORMULATION USING LINEAR INTERPOLATION AND TRIANGULAR CELLS

2011 ◽  
Vol 08 (04) ◽  
pp. 813-824 ◽  
Author(s):  
X. Y. CUI ◽  
S. LIN ◽  
G. Y. LI
Keyword(s):  
Boundary Conditions ◽  
Thin Plate ◽  
Plate Theory ◽  
Weak Form ◽  
Linear Interpolation ◽  
Integration Domain ◽  
Nodal Integration ◽  
Thin Plate Theory ◽  
System Equations ◽  
Gradient Smoothing

This paper presents a thin plate formulation with nodal integration for bending analysis using three-node triangular cells and linear interpolation functions. The formulation was based on the classic thin plate theory, in which only deflection field was required and dealt with as the field variables. They were assumed to be piecewisely linear and expressed using a set of three-node triangular cells. Based on each node, the integration domain has been further derived, where the curvature in the domain was computed using a gradient smoothing technique (GST). As a result, the curvature in each integration domain is a constant whereby the deflection is compatible in the whole problem domain. The generalized smoothed Galerkin weak form is then used to create the discretized system equations where the system stiffness is obtained using simple summation operation. The essential rotational boundary conditions are imposed in the process of constructing the curvature field in conjunction with imposing the translational boundary conditions in the same way as undertaken in the standard FEM. A number of numerical examples were studied using the present formulation, including both static and free vibration analyses. The numerical results were compared with the reference ones together with those shown in the state-of-art literatures published. Very good accuracy has been achieved using the present method.

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