Dynamics of acoustically bound particles
Nicholas St. Clair, Dominique Davenport, Arnold D. Kim, Dustin Kleckner
Abstract
It is well known that scattering from acoustic fields can produce forces on single particles; however, they can also induce interparticle forces due to multiple scattering events. This multiparticle force---here referred to as acoustic binding---is comparable to other acoustic forces when the particles are of order wavelength in diameter. In principle, this force could be used as a tunable method for directing the assembly of particles of mm scales, but has not been extensively explored in previous work. Here, we use a numerical method to compute binding interactions between strongly scattering bodies and find that they can produce stable clusters of particles with approximately wavelength separation. Moreover, we also observe that---depending on the level of viscous damping---these structures can produce driven linear, rotational, or vibrational motion. These effects are a result of the nonconservative and nonpairwise nature of the acoustic binding force and represent contactless manipulation and transport methods with a variety of potential applications.