The selective contactless manipulation and assembly of physical and biological objects at micrometric down to nanometric scales promises tremendous development in fields as diverse as microrobotics, microfluidics, tissue engineering or micro/nano- medicine.

In this regard, acoustical tweezers is a prominent technology since it is non-invasive, biocompatible label-free and enables trapping forces several orders of magnitudes larger than their optical counterparts at same actuation power, hence preventing deleterious heating.

Yet, the widespread dissemination of this technology has been hindered by severe limitations of current systems in terms of selectivity and/or miniaturization and integrability. In this work, the authors have brought the technology to the next level by developing the first flat, transparent, single electrodes selective acoustical tweezers.

These tweezers rely on spiraling transducers obtained by folding a spherical acoustical vortex on a flat piezoelectric substrate. The authors demonstrate the ability of these tweezers to grab and displace micrometric objects in a standard microscopy environment with unique selectivity.

Reference: M. Baudoin et al., Folding a focalized acoustical vortex on a flat holographic transducer: Miniaturized selective acoustical tweezers, Sci. Adv. 2019; 5: eeav1967

Link: https://advances.sciencemag.org/content/5/4/eaav1967/tab-article-info

Contact: Michael Baudoin: michael.baudoin@univ-lille.fr