Structural reconfiguration of multi-particle systems through parametric pumping

Abstract Processes from crystallization to protein folding to robot self-assembly rely on achieving specific configurations of interacting particles. However, precise manipulation of even a small number of particles into more than one configuration without the use of feedback control is still challenging when controlled externally without feedback loops, especially if the interactions are non-conservative. Here we show how one can select, and switch between, specific structures without relying on tuning the energetic landscape of the system. Exploiting that different particle configurations have different mechanical resonances, we use parametric pumping to selectively excite and destroy undesired structures, making the targeted one an absorbing state. We demonstrate this approach with an acoustically levitated five-particle system in the Rayleigh limit, where the interactions are not only non-reciprocal and thus non-conservative, but also non-pairwise. With results from experiments and simulations on three additional systems ranging up to hundreds of particles, we demonstrate the generality of this method, providing a new path for non-invasive structure control of multi-particle systems.