Passive Metasurface Tweezers for Multi‐Scale Orbital Transport and Trapping on Elastic Plates

Abstract

ABSTRACT Acoustic manipulation on solid surfacesis often constrained by limited wave‐field reconfigurability and reliance on complex active excitation, hindering the simultaneous realization of particle confinement and controlled rotation. Here, we present a passive, subwavelength‐encoded platform that enables cross‐scale confinement and orbital manipulation on an open thin plate under single‐channel power‐source excitation. By integrating graded‐phase, high‐transmission labyrinthine superstructures, the platform enables precise spatial phase modulation without electronic modulation. The system preserves flexural wave vortex fields with well‐defined phase singularities over a broad operating bandwidth (∼8 kHz). To elucidate the underlying physics, a phenomenological force framework is established: orbital angular momentum induced by azimuthal phase gradients drives circumferential motion, while amplitude‐gradient‐induced asymmetric interactions provide an effective radial confinement force. This synergistic mechanism facilitates multi‐scale manipulation of objects spanning from sub‐millimeter particles to lightweight centimeter‐scale structures. Furthermore, the vortex chirality can be reversed solely via structural inversion, revealing a passive control strategy governed by spatial symmetry. This work establishes a versatile framework for integrated surface‐wave manipulation, with potential applications in lab‐on‐a‐surface systems.