Effects of non-reciprocal forces in acoustically bound clusters

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.

In particular we will discuss non-reciprocal forces which arise from many body interactions, and how this affects the activity and formation of structure in the system.