To determine the efficacy of our synthetic protocols to obtain microswimmers, we evaluate the active Pèclet numbers (P e) of the unfunctionalised SiO 2 , bulk Pt-functionalised SiO 2 , and the Janus Pt-functionalised SiO 2 . P e ∝ V √ D T D R determines the ratio of the ballistic (V is the propulsion speed) and diffusive (with D T and D R the translational and rotational diffusiv- The inset shows the MSD on a log-log scale. Error bars are the standard error b. Active particle yields (Pe>20) from different synthetic routes (colours as in a.). The error bars correspond to 95% confidence intervals, which were obtained with bootstrapping. All particle tracking investigations were performed using 0.5v/v% H 2 O 2 fuel concentration, and statistics were gathered from at least 130 particle trajectories. ities, respectively) components of motion, and provides a measure of the relative importance of directed motion, ergo, the proportion of active particles. Setting a threshold P e > 20, we find that 68% of the Janus Pt-functionalised particles are active, providing an indirect measure of the yield of our microswimmer fabrication protocol (Figure ). We note that even without the asymmetric functionalisation provided by the Pickering wax-emulsions, 34% of the bulk Pt-functionalised particles surpass the P e > 20 threshold. Spontaneous symmetry breaking of a concentration field and swimming behaviour has also been theorised for symmetric particles at P e = 4 . However, in our case, the bulk-grown films possess inherent asymmetries, which we hypothesise are sufficient to induce minor gradients and thus particle motion. Nonetheless, the doubling in the proportion of microswimmers obtained by purposely introducing asymmetry as well as the higher overall fitted velocities (unfunctionalised SiO 2 = [0.077; 0.096] µms -1 , bulk Pt = [0.63; 0.81] µms -1 , Janus Pt = [1.2; 1.6] µms -1 -95% confidence intervals from bootstrapping) highlight the importance of the anisotropy obtained from using Pickering-wax emulsions.