Acoustic dark lattices generated by composite spiral plates for multi-particle trapping

The interactions of two Bessel acoustic vortices (BAVs) with different topological charges (TCs) have been investigated in detail. The theoretical results show that, with changing the TCs of two BAVs, the intensity distributions of the coupled-BAVs can switch among the petal mode, the acoustic dark lattice (ADL) mode, and the crescent mode, where the positions of the dark spots coincide with the phase singular points. We concentrate on the ADL modes and a composite spiral plate (CSP) is well designed to realize them. It is shown both numerically and experimentally that the CSP can create the ADL modes in air, which also exhibit strong self-healing. Additionally, the CSP is employed to generate ADLs in water. Four-order and six-order ADLs produced by two steel CSPs are used, respectively, to achieve multi-particle trappings in water experimentally. The capacity of the ADLs generated by the simple CSPs to trap multiple micro-particles in desired positions may find applications in biomedicine, including microar-rays, tissue engineering, and regenerative medicine.& COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

The interactions between two Bessel acoustic vortices (BAVs) with different topological charges (TCs) were thoroughly investigated. The results showed that by changing the TCs of the BAVs, the intensity distributions of the coupled-BAVs could switch between the petal mode, the acoustic dark lattice (ADL) mode, and the crescent mode. A well-designed composite spiral plate (CSP) was used to realize the ADL modes, which exhibited strong self-healing properties. Additionally, the CSP was employed to trap multiple micro-particles in water, demonstrating its potential applications in biomedicine.