Dynamic analysis of CMUTs in different regimes of operation

2003-01-01
Bayram, Barış
Ergun, AS
Yaralioglu, GG
Khuri-Yakub, BT
This paper reports on dynamic analysis of an immersed single capacitive micromachined ultrasonic transducer (CMUT) cell transmitting. A water loaded 24 mum circular silicon membrane of a transducer was modeled. The calculated collapse and snapback voltages were 80 V and 50 V, respectively. The resonance frequency, output pressure and nonlinearity of the CMUT in three regimes of operation were determined. These regimes were: a) the conventional regime in which the membrane does not make contact with the substrate, b) the collapsed regime in which the center of the membrane is in constant contact with the substrate, and c) the collapse-snapback regime in which the membrane intermittently makes contact with the substrate and releases. The average membrane displacement was compared as the CMUT was operated in these regimes. A displacement of 70 A in the collapsed regime and 39 Angstrom in conventional regime operation were predicted when a 5 V pulse was applied to the CMUT cell biased at 70 V. The CMUT showed a 2(nd) harmonic at -16 dB and -26 dB in conventional and collapsed regimes of operation, respectively. Collapse-snapback operation provided increased output pressure at the expense of a 3(rd) harmonic at -10 dB. Our simulations predicted that the average output pressure at the membrane could be 90 kPa/V with collapse-snapback operation compared to 4 kPaN with conventional operation.
IEEE International Ultrasonics Symposium

Suggestions

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...
ACOUSTIC CROSSTALK REDUCTION METHOD FOR CMUT ARRAYS
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...
Detailed Noise Analysis of Current-to-Frequency Converters for Precision Analog Accelerometers
Nuzumlali, Omer Lutfi (2016-04-14)
This paper presents a detailed noise analysis of current-to-frequency converters (CFC) for current output precision analog accelerometers. In the proposed method, time domain approach is used instead of frequency domain approach and the standard deviation of the velocity error after a fixed period of time is calculated. The noise analysis demonstrates that the error caused by voltage noises does not increase with time. However, the standard deviation of the error due to the feedback current noise increases ...
Highly Integrated 3 V Supply Electronics for Electromagnetic Energy Harvesters With Minimum 0.4 V-peak Input
Ulusan, Hasan; Zorlu, Ozge; Muhtaroglu, Ali; Külah, Haluk (2017-07-01)
This paper presents a self-powered interface enabling battery-like operation with a regulated 3 V output from ac signals as low as 0.4 V-peak, generated by electromagnetic energy harvesters under low frequency vibrations. As the first stage of the 180 nm standard CMOS circuit, harvested signal is rectified through an ac/dc doubler with active diodes powered internally by a passive ac/dc quadrupler. The voltage is boosted in the second stage through a low voltage charge pump stimulated by an on-chip ring osc...
Performance Analysis of Reduced Common-Mode Voltage PWM Methods and Comparison With Standard PWM Methods for Three-Phase Voltage-Source Inverters
Hava, Ahmet Masum (2009-01-01)
This paper surveys the reduced common-mode voltage pulsewidth modulation (RCMV-PWM) methods for three-phase voltage-source inverters, investigates their performance characteristics, and provides a comparison with the standard PWM methods. PWM methods are reviewed, and their pulse patterns and common-mode voltage (CMV) patterns are illustrated. The inverter input and output current ripple characteristics and output voltage linearity characteristics of each PWM method are thoroughly investigated by analytical...
Citation Formats
B. Bayram, A. Ergun, G. Yaralioglu, and B. Khuri-Yakub, “Dynamic analysis of CMUTs in different regimes of operation,” presented at the IEEE International Ultrasonics Symposium, Honolulu, HI, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52849.