Figure 4.
(Color online) (a) Laser-generated tandem bubble oscillation and jet formation produced inside the PDMS–glass microchannel at an inter-bubble time delay of 0, 1, 2, 3, 4, 5 μs (from top to bottom). High-speed imaging sequences were taken with a framing rate of 1 × 106 frames/s; (b) jet formation from in-phase tandem bubble oscillation; (c) jet formation from out-of-phase tandem bubble oscillation; and vorticity field averaged over t = 100–150 μs after (d) in-phase and (e) out-of-phase tandem bubble oscillation.