Curriculum Vitae - APC - Université Paris Diderot-Paris 7

Figure 3. Quincke rotation: basic principle. A- Unstable surface charge distribution in a weakly conducting fluid
under uniform electric field is applied. The charge distribution evolve to reach a new stationary state, where the
resulting dipoles makes a finite angle with the external field, which results in a net torque on the particles which
rotate in the fluid. Close to an interface, the rotation is transferred in a translation. B: Trajectories of selfpropelled
Quincke rotators in the dilute regime, for three different values of the DC field. The persistence length
of the trajectories increases as the field magnitude increases. Scale bar: 100 microns. C: The mean squared
displacement plotted as a function of time for two field amplitudes. The red dots correspond to field amplitude
close to the rotation threshold (E=0.9 kV/mm). A clear crossover from a ballistic to a diffusive dynamics is
observed. The blue dots correspond to a high field regime (E=2.4 kV/mm).