High-frequency single beam acoustical tweezers for 3D trapping and dynamic axial manipulation of cells and microparticles

Abstract

The 2D trapping and manipulation capabilities of acoustical tweezers based on focused acoustical vortices and Spiraling InterDigitated Transducers (S-IDTs) have been demonstrated both experimentally and numerically {see [Baudoin et al., Sci. Adv. 5, eaav1967 (2019)] for microparticles and [Baudoin et al., Nat. Commun., 11, 4244 (2020)] for cells}. Compared to other technologies, S-IDTs have the advantage to enable the synthesis of high-frequency vortices with trap lateral extension comparable to the cell scale (typically from 5 to 20 μm), which is a necessary condition for selectivity. However, our previous work based on the S-IDTs only demonstrated 2D trapping. Here we investigate numerically the feasibility of 3D trapping of cells and microparticles with a focused vortex beam with large aperture and axial motion of the trapped object by tuning the excitation frequency. This work opens perspectives for 3D advanced cells and microparticles manipulation.