A multi-scale ultrasound platform for manipulating complex biological system

Due to its non-contact, label-free, penetrable nature and favorable biocompatibility, acoustic manipulation has become an essential technique for handling microparticles, cells, droplets, soft materials, and microtissues. Existing approaches largely rely on acoustic radiation-force models for Rayleigh-scale particles. When object dimensions approach or exceed the acoustic wavelength, higher-order scattering, many-body coupling and boundary effects markedly reshape the local field. This leads to deviations between the prescribed acoustic environment and the actual force landscape. Focusing on the resulting bottleneck in complex biological systems, this work systematically examines the distinct acoustic responses across Rayleigh, Mie, and geometrical regimes and outlines a design strategy for a cross-scale acoustic manipulation platform. This provides a reference for a unified Rayleigh–Mie-geometrical co-manipulation model spanning continuous length scales and holds promise for delivering new engineering modalities for organoid microenvironment construction.