Abstract
Microbubbles oscillating nonlinearly in the ultrasound field are used for contrast agents. In particular, microbubbles surrounded by a protein, lipid, or polymer shell show a mechanical property different from micobubbles without shell. This research, after deriving an analytical model and the governing equation including effects of the shell, investigated the dynamical behavior of insonified shell-coated microbubbles by numerical simulation. Our numerical results show that the oscillation center shifts to the side of bubble compression because the surface tension changes with the bubble radius if the bubble shell exists. These results are in qualitative agreement with experimental ones.
