A simple closed-form model to accurately calculate the electromechanical coupling coefficient of CMUTs
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Sazzadur Chowdhury
Sazzadur Chowdhury is a professor in the department of Electrical and Computer Engineering in the University of Windsor and is the director of the MEMS lab in the University. Dr. Chowdhury’s team is dedicated to advance the state-of-the-art in diagnostic medical imaging through advanced ultrasound transducers and solid state radar based tomography for low cost more accurate detection of medical conditions at an early stage when they are easier to cure. Dr. Chowdhury recently received a CFI grant to develop nanotechnology based bio-inspired smart surfaces for more effective drug delivery. His research team is also working to develop advanced sensors for automotive collision avoidance, highway safety, and border security. He is a professional engineer in the province of Ontario and a member of IEEE. He owns 10 USA and Canadian patents in the areas of MEMS based ultrasonic transducers and radars. He published 70 peer reviewed research papers. Dr. Chowdhury received University of Windsor Award for Excellence in Scholarship, Research and Creative Activity in 2015–2019, 2009, 2007, and 2005.
Abstract
A simple highly accurate closed-form model to calculate the electromechanical coupling coefficient of a capacitive micromachined ultrasonic transducer (CMUT) is presented. The model exploits the electrostatic spring softening phenomenon to derive an expression for the energy converted from electrical to mechanical domain and includes the nonlinear change of the CMUT diaphragm stiffness during large deflections. The model has been validated by comparing the model predicted values with experimental results published elsewhere along with the results predicted by some existing models. The comparison shows that the model predicted values are in excellent agreement with experimental results. The model also enables one to quantify the effects of residual stress, bending, and nonlinear stretching of the diaphragm on the transduction efficiency of CMUTs without any computationally intensive finite element analysis method. The model resolves the ambiguity of the absence of electrostatic spring softening effect in some existing models.
Zusammenfassung
Es wird ein einfaches, hochgenaues geschlossenes Modell zur Berechnung des elektromechanischen Kopplungskoeffizienten eines kapazitiven mikrobearbeiteten Ultraschallwandlers (CMUT) vorgestellt. Das Modell nutzt das Phänomen der elektrostatischen Federerweichung, um einen Ausdruck für die Energie abzuleiten, die von einem elektrischen in einen mechanischen Bereich umgewandelt wird, und schließt die nichtlineare Änderung der CMUT-Membransteifigkeit bei großen Auslenkungen ein. Das Modell wurde validiert, indem die prognostizierten Modellwerte mit den an anderer Stelle veröffentlichten experimentellen Ergebnissen verglichen wurden, zusammen mit den Ergebnissen, die von einigen vorhandenen Modellen prognostiziert wurden. Der Vergleich zeigt, dass die modellprognostizierten Werte in hervorragender Übereinstimmung mit den Versuchsergebnissen sind. Das Modell ermöglicht es auch, die Auswirkungen von Restspannung, Biegung und nichtlinearer Dehnung der Membran auf die Transduktionseffizienz von CMUTs ohne rechenintensive Finite-Elemente-Analysemethoden zu quantifizieren. Das Modell löst die Mehrdeutigkeit des Fehlens eines elektrostatischen Federweichungseffekts in einigen vorhandenen Modellen.
Funding source: Natural Sciences and Engineering Research Council of Canada
Award Identifier / Grant number: RGPIN 293218
Funding statement: This research work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC)’s discovery grant number RGPIN 293218.
About the author
Sazzadur Chowdhury is a professor in the department of Electrical and Computer Engineering in the University of Windsor and is the director of the MEMS lab in the University. Dr. Chowdhury’s team is dedicated to advance the state-of-the-art in diagnostic medical imaging through advanced ultrasound transducers and solid state radar based tomography for low cost more accurate detection of medical conditions at an early stage when they are easier to cure. Dr. Chowdhury recently received a CFI grant to develop nanotechnology based bio-inspired smart surfaces for more effective drug delivery. His research team is also working to develop advanced sensors for automotive collision avoidance, highway safety, and border security. He is a professional engineer in the province of Ontario and a member of IEEE. He owns 10 USA and Canadian patents in the areas of MEMS based ultrasonic transducers and radars. He published 70 peer reviewed research papers. Dr. Chowdhury received University of Windsor Award for Excellence in Scholarship, Research and Creative Activity in 2015–2019, 2009, 2007, and 2005.
Acknowledgment
The authors also greatly acknowledge the generous support provided by CMC Microsystems Canada, Angstrom Engineering, Kitchener, ON, and IntelliSense Software Corporation of Woburn, MA.
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Conflict of interest: On behalf of all authors, the corresponding author states that there is no conflict of interest with any third party or person.
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Articles in the same Issue
- Frontmatter
- Beiträge
- Development of a methodical approach for uncertainty quantification and meta-modeling of surface hardness in white layers of longitudinal turned AISI4140 surfaces
- Optimierung der Sensorpositionierung bei schwingungsbasierter Wälzlagerzustandsüberwachung unter Einbezug von Systemeigenmoden
- Berührungslose Messung von Pitchwinkelabweichungen an Windenergieanlagen aus 150 m Entfernung
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- Novel methodology for turbine gas meters error curve modelling across a wide range of operating parameters
- A simple closed-form model to accurately calculate the electromechanical coupling coefficient of CMUTs
- Force measurement of electrodes on a human head model
