Laser-Generated Scholte Waves in Floating Microparticles

Abstract

This study aims to demonstrate the generation and detection of Scholte waves inside polystyrene microparticles. This was proven using both experimental analysis and COMSOL simulation. Microspheres of different sizes were excited optically with a pulsed laser (532 nm), and the acoustic signals were detected using a transducer (40 MHz). On analyzing the laser-generated ultrasound signals, the results obtained experimentally and from COMSOL are in close agreement both in the time and frequency domain. A simplified analysis of Scholte wave generation by laser irradiation for homogeneous, isotropic microspheres is presented. The theoretical wave velocity of the Scholte wave was calculated and found close to our experimental results. A representation of pressure wave motion showing the Scholte wave generation is presented at different times.

Photoacoustic-photothermal visualisation of gastric tissues based on COMSOL

“…There are currently many finite element software, and the large general purpose finite element analysis software ANSYS is able to analyse non-linear problems very well and is mainly used in the mechanical and nuclear industries [7] ，DA is widely used due to its fast calculation speed and high accuracy. There are currently many finite element software, and the large general purpose finite element analysis software ANSYS is able to analyse non-linear problems very well and is mainly used in the mechanical and nuclear industries [8] ； COMSOL Multiphysics software is less influential [9] .It is a mathematical solution to a system of partial differential equations based on the finite element method to simulate real physical phenomena [10] ， The main advantages are a simple interface, the ability to achieve excellent and efficient multi-physics field coupling through any combination of modules, outstanding computational performance, accurate simulation results, and good computation of various physical phenomena [11] .In this study, COMSOL Multiphysics was chosen to visualise and simulate photothermal imaging of gastric cancer. A simplified model of the stomach was constructed and meshed using COMSOL, followed by coupling the coefficient form partial differential equations (in the mathematics module) and the biological heat transfer module in COMSOL.…”