Optical measurement of acoustic radiation pressure of the near-field acoustic levitation through transparent object

TL;DR

This paper introduces a direct measurement method for acoustic radiation pressure distribution in near-field acoustic levitation using pressure-sensitive paint, advancing understanding of levitation forces.

Contribution

It presents the first direct measurement technique for pressure distribution in NFAL, filling a gap in experimental capabilities.

Findings

Successful measurement of pressure distribution on levitated objects

Demonstration of pressure-sensitive paint effectiveness

Enhanced understanding of acoustic levitation forces

Abstract

It is known that macroscopic objects can be levitated for few to several hundred micrometers by near-field acoustic field and this phenomenon is called near-field acoustic levitation (NFAL). Although there are various experiments conducted to measure integrated acoustic pressure on the object surface, up to now there was no direct method to measure pressure distribution. In this study we measured the acoustic radiation pressure of the near-field acoustic levitation via pressure-sensitive paint.