Folding a focalized acoustical vortex on a flat holographic transducer: miniaturized selective acoustical tweezers

TL;DR

This paper introduces a novel flat, compact acoustical tweezers device that uses holographic transducers to precisely manipulate microscopic objects, enhancing performance and miniaturization for applications in microbiology and microrobotics.

Contribution

The development of the first flat, single-electrode focalized acoustical tweezers using holographic transducers folded on a flat substrate is a significant innovation.

Findings

Able to grab and move micrometric objects in microfluidic environments

Demonstrates high selectivity and trapping force

System scalability to higher frequencies

Abstract

Acoustical tweezers based on focalized acoustical vortices hold the promise of precise contactless 3D manipulation of millimeter down to sub-micrometer particles, microorganisms and cells with unprecedented combined selectivity and trapping force. Yet, the widespread dissemination of this technology has been hindered by severe limitations of current systems in terms of performance and/or miniaturization and integrability. In this paper, we unleash the potential of focalized acoustical vortices by developing the first flat, compact, single-electrodes focalized acoustical tweezers. These tweezers rely on holographic Archimedes-Fermat spiraling transducers obtained by folding a spherical acoustical vortex on a flat piezoelectric substrate. We demonstrate the ability of these tweezers to grab and displace micrometric objects in a standard microfluidic environment with unique selectivity. The simplicity of this system and its scalability to higher frequencies opens tremendous perspectives in microbiology, microrobotics and microscopy.