Acoustically Mediated Self-Organization

Acoustic fields can produce trapping forces on single particles, analogous to the optical trapping effect. However, sound can also induce forces between particles due to multiple scattering events. This inter-particle force -- which we refer to as acoustic binding -- can be used to guide the long-range assembly of particles on wavelength scales. Here we describe how numerical modelling is used to study these forces and the structures that they produce. We will also discuss some unexpected behavior which arises as a consequence of the non-linear and non-pairwise nature of these interaction forces.