Extended Data Fig. 9: Dipole reconfiguration induced by underwater streaming.

a, Schematic depiction of the underwater streaming experiment. b, Polarized light micrographs of the domain walls created by underwater streaming. Single-headed arrows indicate the orientation of elastic dipoles, with the arrow color representing the orientation as defined in Extended Data Fig. 2a. Crossed, double-headed arrows indicate the direction of the crossed polarizers. In this experiment, a global underwater flow was first applied to pre-align the dipoles, followed by a localized underwater streaming to selectively reorient dipoles in specific regions. This approach resulted in the formation of bidomain structures that cannot be achieved through droplet collision alone, notably without the emergence of Ising or Néel walls, as discussed in Fig. 3b of the main text.