Midair Single-Sided Acoustic Levitation in High-Pressure Regions of Zero-Order Bessel Beams.

Acoustic levitation enables noncontact manipulation using sound waves. While conventional methods entrap particles at pressure nodes (zero-pressure region surrounded by high pressure), we demonstrate stable acoustic levitation and translation in midair within a high-pressure axial core of a zero-order Bessel beam for the first time. The trap operates at a long working distance, up to 397 mm (46.6λ), supports simultaneous multiparticle levitation, and maintains stability over obstacles. Our work establishes a new paradigm for single-sided acoustic manipulation in midair.