Development of a travelling/standing wave switching acoustic manipulation platform for ICF capsules rotation and sorting

Abstract

Inertial Confinement Fusion (ICF) achieves hydrogen isotope fusion by compressing ICF capsules to extreme densities and temperatures. The surface quality of the capsules significantly affects laser focusing and energy transfer, making precise surface inspection critical for successful fusion. However, traditional manipulation platforms often rely on mechanical contact, which risks damaging the fragile capsules and compromising inspection accuracy. To address this, a novel travelling/standing wave switching acoustic manipulation platform is proposed for non-destructive capsule inspection. The platform consists of a vibrator and a Polydimethylsiloxane (PDMS) channel. The vibrator utilizes two piezoelectric ceramics to excite its resonance modes. One piezoelectric ceramic excites a travelling wave mode and creates a rotating travelling wave acoustic field in the water, thus driving the capsule to rotate at the center of the water. The second piezoelectric ceramic excites two additional standing wave modes of different orders, establishing a standing wave with distinct distribution characteristics in the water. Under the influence of these two acoustic fields, the ICF capsule exhibits varying migration distances. By designing a PDMS channel with a collection chamber, lateral forces at the liquid surface are introduced into the acoustic field, facilitating the migration and capture of the ICF capsule into the collection chamber. Through switching between a travelling wave mode and two standing wave modes, the proposed acoustic manipulation platform allows for precise control of the capsule rotation and mass sorting. A general simulation method for piezoelectric acoustic manipulation devices is also developed, incorporating vibration mode acoustic field, acoustic streaming field, and particle tracking simulations. These simulations validated the feasibility of the proposed rotation and sorting scheme and determined the size parameters of the acoustic manipulation platform. Experimental results demonstrate that the platform can achieve precise rotation and quality sorting of capsules, proving its non-destructive, efficient, high-precision, and easy-to-operate advantages, with promising applications in ICF capsule inspection.