Characterization of dual-electrode CMUTs: Demonstration of improved receive performance and pulse echo operation with dynamic membrane shaping


Guldiken R. O. , Balantekin M. , Zahorian J., Degertekin F. L.

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL, vol.55, no.10, pp.2336-2344, 2008 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 55 Issue: 10
  • Publication Date: 2008
  • Doi Number: 10.1109/tuffc.933
  • Title of Journal : IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
  • Page Numbers: pp.2336-2344

Abstract

A 1-D dual-electrode CMUT array for intracardiac echocardiography (ICE) with a center frequency of 8 MHz has been designed, fabricated, and used to demonstrate the potential of dual-electrode CMUTs. Using a dual-electrode CMUT, 9 dB higher receive signal level is obtained over the 6 dB fractional bandwidth as compared with a conventional CMUT with an identical center electrode biased close to its collapse voltage. Because the same device shows a 7.4 dB increase in maximum pressure output, 16.4 dB overall improvement in transduction performance has been achieved as compared with conventional CMUT. A net peak output pressure of 1.6 MPa on the dual-electrode CMUT membrane with tone burst excitation at 12 MHz is also reported. The frequency response of the dual-electrode CMUT is similar to that of a conventional CMUT with the same membrane geometry with about 15% increase in the center frequency. Monostatic operation of dual-electrode CMUTs shows that the high performance of the transducer is applicable in typical pulse-echo imaging mode of operation. With dynamic shaping of the CMUT membrane to optimize the transmit-and-receive modes of operation separately during each pulse-echo cycle, dual-electrode CMUT is a highly competitive alternative to its piezoelectric counterparts.