  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.
