Figure 9. Spontaneous fusion and fission for ring-like clusters with the same vorticity.

(b) Emerging states for all the swimmers types as a function of reduced self-propulsion velocity v/v₀—see Supplementary Movies 4–6. Different states are indicated by different colours and fused states are sketched in panel a and characterized as: (i) a spontaneously fused rotating dimer, (ii) an emerging closed ring of N=10 swimmers, (iii) a closed ring of N=8 swimmers with counter rotating microswimmers, (iv) induced fission into various fragments and (v) spontaneous fission of the individual initial ring-like clusters.