• Guanjia Zhao Guanjia Zhao
  • Nam-Trung Nguyen Nam-Trung Nguyen
  • Martin Pumera Martin Pumera

The motion directiolity of self-propelled bubble-jet microengines is influenced by their velocities and/or viscosity of the media in which they move. The influence of the fuel concentration from 1 to 3 wt% of H2O2 in 0.5% steps and of the glycerol fraction from 0 to 64% in aqueous solution on the directiolity of the microjets motions is examined systematically. We show that with decreasing Reynolds numbers of the system (that is, with increasing viscosity or decreasing velocity of the microjets), the directiolity of the motion shifts from circular to linear motion. This translates to a shorter travel time towards a desigted target for the microjets despite moving at a slower speed, since the movements are linear instead of circular. We show that such dependence of trajectories of microjets on Re is a general issue. This observation has a strong implication for the real-world applications of microjets.