Patterned Plates Use Acoustic Vibrations to Manipulate Objects Without Complex Electronics

Researchers in China have developed a method to manipulate physical objects across solid surfaces using structured acoustic vibrations, bypassing the multi-channel electronic control systems typically needed to generate complex wave patterns.

Led by Zhao Liuxian and Yang Jun of the Institute of Acoustics at the Chinese Academy of Sciences, alongside Bi Chuanxing of Hefei University of Technology, the team published their findings in Advanced Science on Sept. 19, according to a report by TechXplore (https://techxplore.com/news/2026-09-patterned-plate-surface-vibrations-complex.html).

Conventional systems that use vortex waves—swirling wave fields carrying orbital angular momentum—usually rely on dynamic wavefront modulators or multi-channel phased arrays to maintain precise phase synchronization. The researchers eliminated those active electronic components by pre-encoding the required azimuthal phase profile directly into the physical layout of a thin plate using labyrinthine subwavelength structures.

These passive subwavelength units act as localized phase modulators. When subjected to single-channel excitation, the plate generates flexural-wave vortices with prescribed topological charges without requiring active phase tuning.

Laboratory experiments demonstrated that the resulting wave field features a low-amplitude vortex core and non-uniform amplitude distribution, creating radial confinement. Simultaneously, orbital angular momentum transferred by the azimuthal phase gradient provides tangential driving force. Combined, these forces allow objects to be trapped, driven in orbital paths, or rotated in place.

The passive metasurface manipulated objects across several size thresholds, including submillimeter particles, millimeter-scale particles, and lightweight centimeter-scale structures. Submillimeter particles were confined near the core or driven along orbital paths, millimeter-scale particles traced stable orbital trajectories, and centimeter-scale objects underwent sustained rotation.

The researchers also demonstrated that reversing the sign of the structural topological charge reverses the phase gradient and angular momentum direction, switching orbital motion between clockwise and counterclockwise paths. The authors suggest the passive approach could simplify designs for micromechanical actuation, surface particle transport, intelligent structures, and lab-on-a-surface systems.