摘要
Acoustic vortex tweezers (AVT) enable contactless trapping and manipulation of gas microbubbles using helical ultrasound wavefronts that carry orbital angular momentum and generate a toroidal acoustic potential. In a tornado-inspired implementation, the vortex beam forms a stable 3-D trap that captures individual microbubbles against buoyancy and flow, and then transports, rotates, merges, or releases them with programmable trajectories. This deterministic control creates a new microbubble robotics modality that decouples positioning from destructive insonation. Leveraging this capability, AVT can intentionally cluster microbubbles to amplify cavitation activity at a designated site, thereby enhancing drug delivery while maintaining spatial confinement. Vortex-driven clustering concentrates acoustic nuclei, promotes repeatable cavitation events, and increases local permeability and payload transport relative to dispersed bubbles. By mapping operational regimes of trapping, clustering, radiation-force action, and bubble destruction, the combined studies provide design rules for selecting frequency, pressure, duty cycle, and vortex order for either gentle manipulation or strong cavitation-assisted delivery. Together, these results position AVT as a programmable ultrasound platform for precision microbubble control and cavitation-enhanced therapeutics, including targeted vascular delivery.