From radio-electronics signal analysis to biological samples actuation,surface acoustic waves (SAW) are involved in a multitude of modern devices.Despite this versatility, SAW transducers developed up to date only authorizethe synthesis of the most simple standing or progressive waves such as planeand focused waves. In particular, acoustical integrated sources able togenerate acoustical vortices (the analogue of optical vortices) are missing. Inthis work, we propose a flexible tool based on inverse filter technique andarrays of SAW transducers enabling the synthesis of prescribed complex wavepatterns at the surface of anisotropic media. The potential of this setup isillustrated by the synthesis of a 2D analog of 3D acoustical vortices, namely"swirling surface acoustic waves". Similarly to their 3D counterpart, theyappear as concentric structures of bright rings with a phase singularity intheir center resulting in a central dark spot. Swirling SAW can be useful infragile sensors whose neighborhood needs vigorous actuation, and may also serveas integrated transducers for acoustical vortices. Since these waves areessential to fine acoustical tweezing, swirling SAW may become the cornerstoneof future micrometric devices for contactless manipulation.
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