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

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.