Micromachined piezoelectric polymer membrane acoustic sensor

T. Y. Lam, Kwok Ho Lam, H. L W Chan

Research output: Journal article publicationConference articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

This paper reports on a 2.3 mm × 2.3 mm polymer micro- electromechanical systems (MEMS) for air transducer applications. The MEMS, used as a receiver of ultrasonic signal, has a suspended membrane structure. A 2.7 μm thick poly(vinylidene fluoridetrifluoroethylene) [P(VDF-TrFE)] 70/30 mol% copolymer was spun on a silicon dioxide/silicon substrate and then poled in-situ. The Si substrate was then etched from the backside by anisotropic chemical etching in KOH to produce a P(VDF-TrFE)/SiO2/Si suspended membrane structure. The displacement of the membrane was measured by means of a laser vibrometer. The maximum deflection at the center of the membrane was 0.9 μm at 40.8 kHz under an input drive of 7 V. A commercial air transducer was used as the transmitter to emit ultrasound at 40.8 kHz. The MEMS acoustic transducer, which has similar resonance frequency, was used as the receiver. The temporal response of the MEMS and its sensitivity were measured. The result suggested that the MEMS has potential for monitoring ultrasound emission.
Original languageEnglish
Pages (from-to)31-37
Number of pages7
JournalIntegrated Ferroelectrics
Volume76
DOIs
Publication statusPublished - 1 Dec 2005
EventSeventeenth International Symposium on Integrated Ferroelectrics, ISIF-17 - Shanghai, China
Duration: 17 Apr 200520 Apr 2005

Keywords

  • MEMS
  • P(VDF-TrFE)
  • Vibrating membrane

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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