Fig. 2. Hydrodynamic flows generated by the synchronous spinners.

(A) The flows velocity field as obtained from particle image velocimetry, (B) the local vorticity field, and (C) flows streamlines at fH = 90 Hz and ρ = 0.0186 σ−2. The spinners are shown in black as retrieved from the original microscopy image. Scale bars, 2 mm.