Diamond-based capacitive micromachined ultrasonic transducers

Date

2012-02-01

Author

Bayram, Barış

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Capacitive micromachined ultrasonic transducers (CMUTs) employing diamond membranes are demonstrated. The design, finite element modeling, microfabrication, and experimental characterization of diamondbased CMUTs are reported. Ultrananocrystalline diamond having a chemical mechanical polished silicon dioxide interlayer deposited via high temperature oxide (HTO) process at 850 degrees C in a low pressure chemical vapor deposition (LPCVD) furnace is employed as the membrane to form vacuum sealed cavities using plasma-activated direct bonding technology. Electrical impedance, deflection, and transmission measurements of a fabricated CMUT are performed in air using an impedance analyzer, a white light interferometer and a hydrophone, respectively. Experimental results verify the accuracy of finite element modeling. Diamond-based CMUTs possess 3-dB fractional bandwidth of 3% at a center frequency of 1.74 MHz in air. Our experimental results demonstrate diamond as an alternate membrane material for CMUTs, and that diamond can be employed in novel microelectromechanical devices.

Subject Keywords

Capacitive micromachined ultrasonic transducer, Ultrananocrystalline diamond, Plasma-activated direct bonding, Microelectromechanical devices

URI

https://hdl.handle.net/11511/35991

Journal

DIAMOND AND RELATED MATERIALS

DOI

https://doi.org/10.1016/j.diamond.2011.11.006

Collections

Department of Electrical and Electronics Engineering, Article

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Diamond-Based Capacitive Micromachined Ultrasonic Transducers in Immersion Cetin, Ahmet Murat; Bayram, Barış (2013-02-01) Diamond is a superior membrane material for capacitive micromachined ultrasonic transducers (CMUTs). By using ultrananocrystalline diamond (UNCD) membrane and plasma-activated wafer bonding technology, a single diamond-based circular CMUT is demonstrated and operated in immersion for the first time. The diamond-based CMUT, biased at 100 V, is excited with a 10-cycle burst of 36 Vp-p sine signal at 3.5 MHz. Pressure generated on a 2-D plane coincident with the normal of the CMUT is measured using a broadband...
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...
Flexible supercapacitor electrodes with vertically aligned carbon nanotubes grown on aluminum foils Dogru, Itir Bakis; Durukan, Mete Batuhan; Turel, Onur; Ünalan, Hüsnü Emrah (2016-06-01) In this work, vertically aligned carbon nanotubes (VACNTs) grown on aluminum foils were used as flexible supercapacitor electrodes. Aluminum foils were used as readily available, cheap and conductive substrates, and VACNTs were grown directly on these foils through chemical vapor deposition (CVD) method. Solution based ultrasonic spray pyrolysis (USP) method was used for the deposition of the CNT catalyst. Direct growth of VACNTs on aluminum foils ruled out both the internal resistance of the supercapacitor...
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...

Citation Formats

B. Bayram, “Diamond-based capacitive micromachined ultrasonic transducers,” DIAMOND AND RELATED MATERIALS, pp. 6–11, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35991.