Electro-mechanical-acoustic coupled dynamic modeling and experimental validation of acoustic tweezer

Abstract

Inertial confinement fusion (ICF) imposed stringent demands on the quality of the ICF microspheres. To achieve non-destructive manipulation during the detection process of ICF microspheres, a novel piezoelectric acoustic tweezer based on the standing wave is proposed. This tweezer addresses damage issues caused by hard-contact handling by utilizing six piezoelectric plates and a metal container to generate controllable acoustic fields in water. Two acoustic fields are produced by exciting the 2nd- and 6th-order bending vibration modes of the container, respectively, each capable of transmitting and positioning microspheres. By adjusting the working sequence and duration of the two acoustic fields, microspheres with different diameters can be automatically sorted. Additionally, a visual feedback control system is developed based on the proposed acoustic tweezer, enabling closed-loop control of ICF microsphere motion. To reveal the vibration characteristics and distribution characteristic of vibration-induced acoustic field of the acoustic tweezer, a universal electro-mechanical-acoustic coupled dynamic model of the acoustic tweezer is developed for the first time using the transfer matrix method. The resonant frequency changes of the acoustic tweezer before and after adding water, the vibration shapes, the acoustic pressure distribution in water, and the magnitude of the acoustic radiation force acting on the ICF microsphere are calculated using this model. The correctness of the dynamic model is validated through vibration characteristic testing of the acoustic tweezer prototype. Finally, manipulation experiments of ICF microspheres are conducted. The results demonstrate that the proposed acoustic tweezer effectively facilitates the automatic transmission, positioning, and diameter sorting of ICF microspheres. The acoustic tweezer holds the advantages of non-destructive, high-precision, favorable controllability, and easy manufacturing, presenting a significant potential application for non-destructive detection of ICF microspheres.