Development of a Spherically Focused Capacitive-film Air-coupled Ultrasonic Transducer

  • Song, Jun-Ho (Center for Nondestructive Evaluation, Iowa State University) ;
  • Chimenti Dale E. (Department of Aerospace Engineering, Iowa State University)
  • Published : 2005.12.30

Abstract

We have built a spherically focused, not using acoustic mirrors, capacitive micromachined air-coupled ultrasonic transducer. A flexible backplate of a copper/polyimide backplate is used, permitting it to conform to a spherically shaped substrate. The backplate is patterned with $40-{\mu}m$ depressions having $80-{\mu}m$ center-to-center spacing. A $6-{\mu}m$ thick aluminized Mylar film completing the transducer is deformed to allow it to conform to the spherical backplate. The device's frequency spectrum is centered at 805kHz with -6dB points at 440 and 1210kHz.

Keywords

References

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