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

Gurpreet Singh Gill, Sanjay Kumar, Ravindra Mukhiya, Vinod Kumar Khanna


In this paper, Finite Element Method (FEM)-based design and simulation of circular capacitive micromachined ultrasonic transducer (CMUT) has been discussed. The FEM simulation of CMUT is accomplished by using MEMCAD tools CoventorWare® and COMSOLTM. The simulation has been performed for air-coupled CMUT devices in which the resonance frequency of the designed CMUT device is 3.9 MHz. Moreover, the simulation results for resonance frequency and pull-in voltage show good agreement with analytical calculations. Finally, a device layer transfer fabrication process flow is also proposed to develop the MEMS-based CMUT devices.


CMUT; FEM modelling; Pull-in voltage; Resonance frequency; Wafer bonding.

Article Metrics

Abstract view : 146 times
PDF - 94 times

Full Text:



A. Carovac, F. Smajlovic and Dzelaludin Junuzovic, Application of ultrasound in medicine, Acta Informatica Medica, 19, 2011, 168-171.

X. Jin, I. Ladabaum and B. T. Khuri-Yakub, The microfabrication of capacitive ultrasonic transducers, Journal of Microelectromechanical Systems, 7, 1998, 295-302.

I. Ladabaum, B. T. Khuri‐Yakub and D. Spoliansky, Micromachined ultrasonic transducers: 11.4 MHz transmission in air and more, Applied Physics Letters, 68, 1998, 7.

H. T. Soh, I. Ladabaum, A. Atalar, C. F. Quate and B. T. Khuri‐Yakub, Silicon micromachined ultrasonic immersion transducers, Applied Physics Letters, 69, 1998, 3674.

A. Arora, R. Gopal, V. K. Dwivedi, C. Shekhar, B. Ahmad, Rudra Pratap and P. J. George, Fabricating capacitive micromachined ultrasonic transducers with wafer bonding technique, Journal of Microelectromechanical Systems, 12(2), 2003, 128-137.

A. S. Ergun, G. G. Yaralioglu and B. T. Khuri-Yakub, Capacitive micromachined ultrasonic transducers: theory and technology, Journal of Aerospace Engineering, 16, 2003, 76-84.

J. Joseph, S. G. Singh and S. R. K. Vanjari, Fabrication of SU-8 based capacitive micromachined ultrasonic transducer for low frequency therapeutic applications, Proceedings of 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Milan, Italy, 2015, 1365-1368.

A. S. Erguri, Y. Huang, X. Zhuang, O. Oralkan, G. G. Yarahoglu and B. T. Khuri-Yakub, Capacitive micromachined ultrasonic transducers: fabrication technology, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 52, 2005, 2242-2258.

K. K. Park, H. Lee, M. Kupnik and B. T. Khuri-Yakub, Fabrication of capacitive micromachined ultrasonic transducers via local oxidation and direct wafer bonding, Journal of Microelectromechanical Systems, 20, 2011, 95-103.

R. Mukhiya, Aditi, K. Prabakar, M. Raghuramaiah, J. Jayapandian, R. Gopal, V. K. Khanna and C. Shekhar, Fabrication of capacitive micromachined ultrasonic transducer arrays with isolation trenches using anodic wafer bonding, IEEE Sensors Journal, 15, 2015, 5177-5184.

R. Sharma, R. Agarwal and A. A. Arora, Collapse mode characteristics of parallel plate ultrasonic transducer radiating in air and water, Sensors & Transducers Journal, 196, 2016, 52-56.

H. Wang, X. Huang, L. Yu, Q. Ding, H. Zhang, C. He and W. Zhang, Hybrid cell structure for wideband CMUT: design method and characteristic analysis, Micromachines, 12(10), 2021, 1180.

M. Rahman and S. Chowdhury, An accurate model for pull-in voltage of circular diaphragm capacitive micromachined ultrasonic transducers (CMUT), 2009. https://www.vlsi.uwindsor.ca/presentations/2009/An Accurate Model for Pull-in Voltage of Circular.pdf (accessed October 2, 2021).

G. Gill, S. Kumar, R. Mukhiya and V. K. Khanna, FEM-based study of CMUT cell for vacuum-sealed and unsealed cavities, 3rd International Conference on Emerging Technologies: Micro to Nano, Solapur, India, 2017.

M. J. Madou, Fundamentals of Microfabrication, CRC Press, 2002.

G. S. Gill, T. Singh and M. Prasad, Study of FBAR response with variation in active area of membrane, AIP Conference Proceedings, 1724, 2016, 020040.

G. S. Gill and M. Prasad, Development of film bulk acoustic wave resonator: a review, Sensor Letters, 14(4), 2016, 346-361.

G. S. Gill, M. Zawierta, D. K. Tripathi, M. Martyniuk, K. K. M. B. Dilusha Silva, G. Putrino, A. Keating and L. Faraone, Modelling and fabrication of anti-stiction features for electrostatically actuated microsystems, Proceedings of 2018 Conference on Optoelectronic and Microelectronic Materials and Devices, Perth, Australia, 2018, 7-10.


  • There are currently no refbacks.