We investigate experimentally the detailed dynamics of how an existing microbubble $B_1$ is impacted and shattered by another nearby pulsed-laser-induced microbubble $B_2$, and the backward interaction on $B_2$ in a thin liquid layer. Mediated by the flow field, potential energy can be accumulated or lost through the alternate compression and expansion of the two bubbles. The symmetry breaking induced by the presence of the nearby counterbubble generates push-pull-type alternate forward and backward axial jetting on the compressed bubble associated with the elongated shape or even entrainment of the counterexpanding bubble into the jet-indented boundary. The strong penetrating axial jet through $B_1$, and its interplay with the transverse jets by the flow field surrounding $B_1$ in the first compression stage and the second expanding stage of $B_1$ lead to a complicated fragmentation pattern of $B_1$. Increasing the interbubble interaction by decreasing the interbubble distance causes $B_2$ to become entangled with $B_1$ through its entrainments into the backward axial jet-indented region of $B_2$, in the expansion phase of $B_2$. At the extreme of large laser energy for $B_2$, the leftward reexpansion of $B_1$ is suppressed. The strong shear flow field generates many tiny bubbles around the liquid-gas boundaries of the two axial jet-induced major daughter bubbles from $B_1$. The detailed interaction behaviors over a broad range of the energy of $B_2$, 0.14–$0.55\mu \text{J}$ (corresponding to the maximum bubble expansion energy), and of the interbubble distance (170–$500\mu \text{m}$) are presented and discussed.

• Received 26 May 2007

DOI:https://doi.org/10.1103/PhysRevE.77.026304