Wave momentum shaping for moving objects in heterogeneous and dynamic media

TL;DR

This paper presents a method to manipulate objects using sound waves in complex, dynamic media by iteratively shaping wave momentum based on real-time scattering measurements, without needing detailed medium information.

Contribution

It introduces a novel approach for wave-based object manipulation in disordered and moving environments, overcoming previous environmental control limitations.

Findings

Successful manipulation of objects in dynamic media

No prior knowledge of medium properties needed

Real-time scattering matrix measurement enables control

Abstract

Light and sound waves have the fascinating property that they can move objects through the transfer of linear or angular momentum. This ability has led to the development of optical and acoustic tweezers, with applications ranging from biomedical engineering to quantum optics. Although impressive manipulation results have been achieved, the stringent requirement for a highly controlled, low-reverberant, and static environment still hinders the applicability of these techniques in many scenarios. Here, we overcome this challenge and demonstrate the manipulation of objects in disordered and dynamic media, by optimally tailoring the momentum of sound waves iteratively in the far field. The method does not require information about the object's physical properties or the spatial structure of the surrounding medium but relies only on a real-time scattering matrix measurement and a positional guidestar. Our experiment demonstrates the possibility of optimally moving and rotating objects, extending the reach of wave-based object manipulation to complex and dynamic scattering media. We envision new opportunities for biomedical applications, sensing, or manufacturing.