Measuring elastic properties of bones and silicon from V(z) curve generated by multiply reflected signals

T. Kundu, C. S. Jørgensen

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Acoustic microscopes can be used to measure Rayleigh and longitudinal or P-wave speeds in a specimen at microscopic resolution. The wave speeds are obtained from the interference pattern as a function of the defocus distance or V(z) curve. The received signal voltage amplitude V is generated by two beams - the normally reflected central beam and a non-specularly reflected beam that strikes the fluid-solid interface at critical angle. It is shown in this paper that instead of analyzing the interference pattern between these two beams if we consider two other beams that follow the same path but travel through the coupling fluid multiple times before interfering then the V(z) curve generated by this higher order interference gives more accurate values for the material properties. The spacing distance between two successive dips of the V(z) curve is smaller for the higher order interference. The higher order interference, although weaker, gives more accurate results. Justification for the greater accuracy of the higher order interference is given in the paper. Material properties of silicon and bone are obtained by the new technique. Bones are microscopically heterogeneous and anisotropic. Anisotropic properties of homogeneous specimens can be obtained by the line focus acoustic microscope; however, it does not work when the specimen is microscopically heterogeneous. An attempt has been made here to obtain anisotropic properties of bones using point focus lens.

Original languageEnglish (US)
Pages (from-to)515-524
Number of pages10
JournalUltrasonics
Volume39
Issue number7
DOIs
StatePublished - Apr 1 2002

    Fingerprint

Keywords

  • Acoustic microscope
  • Bone
  • Elastic properties
  • Elastic waves
  • Material characterization
  • Silicon

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

Cite this