Acoustic radiation force of an elastic spherical shell with an eccentric droplet in plane wave acoustic field

Based on the application of acoustic waves in cell manipulation, a model consist of an elastic spherical shell and eccentric droplet is established to simulate a eukaryotic cell and analyze the acoustic radiation force (ARF) on the cell. In this paper, we derived an exact expression for the ARF on the liquid-filled spherical shell. The influence of eccentric distance, radius of the eccentric droplet and impedance of the medium inside the liquid-filled spherical shell on the ARF are analyzed numerically. Results show that the ARF is very sensitive to the position and size of the eccentric droplet. As the eccentricity of the eccentric droplet increases, the ARF becomes greater. In the low frequency region (ka<3) the resonance peak point increases, and the position of the curve ventral point shifts in the high frequency region (ka>3) with the increase of the radius of the eccentric droplet. The effect of the position variations on the ARF is more significant than radius change, and the impact of both will be promoted on each other. The ARF as a function of ka is mainly affected by the variation of the nucleus characteristic impedance. The ARF amplitude around ka=5 increases and the position of the ventral point tends to shift to the right with the enlargement of the nucleus impedance. Therefore, the radiation response at a certain frequency or cell size range can be enhanced when the nuclear impedance increase. The results of this paper provide theoretical basis for the cell sorting and targeted therapy.