Analytical calculation of collapse voltage of CMUT membrane

Nikoozadeh, A
Bayram, Barış
Yaralioglu, GG
Khuri-Yakub, BT
Because the collapse voltage determines the operating point of the capacitive micromachined ultrasonic transducer (CMUT), it is crucial to calculate and control this parameter. One approach uses parallel plate approximation, where a parallel plate motion models the average membrane displacement. This usually yields calculated collapse voltage 25 percent higher than the actual collapse voltage. More accurate calculation involves finite element method (FEM) analysis. However, depending on the required accuracy, the computation time may require many hours.


Influence of the electrode size and location on the performance of a CMUT
Bayram, Barış; Ergun, AS; Khuri-Yakub, BT (2001-01-01)
The collapse voltage of micromachined capacitive ultrasonic transducers (CMUT) depends on the size, thickness, type, and position of the metal electrode within the membrane. This paper reports the result of a finite element study of this effect. The program (ANSYS 5.7) is used to model a circular membrane on top of a Si substrate covered by a Si3N4 insulation layer. We find that the collapse voltage increases in proportion to the metal thickness for constant membrane thickness. The collapse voltage of a mem...
Bayram, Barış; Kupnik, Mario; Khuri-Yakub, Butrus T. (2006-01-01)
This paper reports on the finite element analysis (FEA) of crosstalk in capacitive micromachined ultrasonic transducer (CMUT) arrays. Finite element calculations using a commercial package (LS-DYNA) were performed for an immersed I-D CMUT array operating in the conventional and collapsed modes. LS-DYNA was used to model the crosstalk in CMUT arrays under specific voltage bias and excitation conditions, and such a modeling is well worth the effort for special-purpose CMUT arrays for ultrasound applications s...
Experimental characterization of collapse-mode CMUT operation
Oralkan, Omer; Bayram, Barış; Yaralioglu, Goksen G.; Ergun, A. Sanli; Kupnik, Mario; Yeh, David T.; Wygant, Ira O.; Khuri-Yakub, Butrus T. (2006-08-01)
This paper reports on the experimental characterization of collapse-mode operation of capacitive micromachined ultrasonic transducers (CMUTs). CMUTs are conventionally operated by applying a direct current (DC) bias voltage less than the collapse voltage of the membrane, so that the membrane is deflected toward the bottom electrode. In the conventional regime, there is no contact between the membrane and the substrate; the maximum alternating current (AC) displacement occurs at the center of the membrane. I...
Analysis and Characterization of DC Bus Ripple Current of Two-Level Inverters Using The Equivalent Centered Harmonic Approach
Ayhan, Ufuk; Hava, Ahmet Masum (2011-09-22)
The dc bus PWM ripple current of three-phase two-level voltage source inverters is a function of the PWM method, the load current magnitude, power factor angle, and the modulation index. Thus, the ripple current characteristics are highly involved and difficult to understand. Using the double Fourier integral approach, this paper investigates the ripple current characteristics thoroughly for a wide range of operating conditions and PWM methods. Then, the equivalent harmonic approach is used to lump the ripp...
Residual stress and Young's modulus measurement of capacitive micromachined ultrasonic transducer membranes
Yaralioglu, GG; Ergun, AS; Bayram, Barış; Marentis, T; Khuri-Yakub, BT (2001-01-01)
Membranes supported by posts are used as vibrating elements of capacitive micromachined ultrasonic transducers (CMUTs). The residual stress built up during the fabrication process determines the transducer properties such as resonance frequency, collapse voltage, and gap distance. Hence, it is important to evaluate and control the stress in thin film CMUT membranes. The residual stress in the membrane causes significant vertical displacements at the center of the membrane. The stress bends the membrane post...
Citation Formats
A. Nikoozadeh, B. Bayram, G. Yaralioglu, and B. Khuri-Yakub, “Analytical calculation of collapse voltage of CMUT membrane,” 2004, Accessed: 00, 2020. [Online]. Available: