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Updated: Jun 2, 2026
10:21
Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Acoustic field radiated into a transversely isotropic solid from a small aperture spherical surface
1School of Physics, University of the Witwatersrand, Wits 2050, South Africa. arthur.every@wits.ac.za
Ultrasonics
|April 26, 2011
Summary
This study models acoustic fields for a scanning probe tip designed to measure near-surface elastic properties. The tip focuses acoustic waves, and reflectivity changes reveal material compliance.
Area of Science:
- Acoustic field modeling
- Materials science
- Nanotechnology
Background:
- Scanning probe microscopy requires high-resolution measurement of material properties.
- Accurate modeling of acoustic fields is crucial for designing advanced probes.
- Understanding wave propagation in anisotropic materials is essential for high-frequency applications.
Purpose of the Study:
- To model the acoustic field of a scanning probe tip for elastic property measurement.
- To investigate the influence of surface curvature and material anisotropy on acoustic focusing.
- To develop a robust method for characterizing near-surface mechanical properties.
Main Methods:
- Finite element analysis (FEA) using ABAQUS/Explicit on an irregular mesh.
- Analytical modeling employing ray tracing and Green's function methods.
- Validation through consistency checks between FEA and analytical approaches.
Main Results:
- The study quantifies the impact of tip curvature and material anisotropy on focal length and spread.
- Consistent results were obtained between numerical and analytical modeling techniques.
- The developed model accurately predicts acoustic field behavior across a range of frequencies.
Conclusions:
- The acoustic field modeling approach is effective for designing high-resolution scanning probe tips.
- The findings enable precise measurement of local, frequency-dependent material compliance.
- This work advances the capability for non-destructive evaluation of solid and surface structures.
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