Fig. 3. Pluripotent colloids.

a Heterodimers exhibit different functions as a function of their number of neighbors n. Heterodimers stand vertically in an optical trap (light blue). For n = 0 heterodimers navigate freely. For n = 1 or 2, the structure is unstable and the heterodimers detach. For n = 3 (purple) or 4 (red), heterodimers orient with respect to the local tangent u_t, with ${\overline{\mathrm{\Phi }}}_3~\pi /4$ and ${\overline{\mathrm{\Phi }}}_4~\pi /2$, respectively, and exert a force along their propulsion direction. For n = 5 or 6 (green), heterodimers are vertical and exert attractive interactions. b Histograms of the angles Φ of heterodimers for n = 3 (blue circles) and n = 4 (red squares) obtained from analysis of slender micromachines of different lengths. c Measured angular velocities ω for 22 different machines (1 color and 4 data points per machine), plotted against the prediction Ω_G obtained by tracking of the instantaneous orientation and position of all constitutive swimmers in eq. (2). c Inset, mean value $\overline{\omega }$ plotted against ${\overline{\mathrm{\Omega }}}_{\mathrm{G}}$ predicted from our simple model with fixed orientations Φ(n = 3) = π/4 and Φ(n = 4) = π/2 (see main text). d Projected translational speed measured by averaging data from all 22 structures plotted against the predicted translational speed v_G from eq. (2). Black dashed lines in (c) and (d) indicate unity slopes. Error bars are 1 standard deviation.