  Different propulsion mechanisms have been suggested for describing the motion
of a variety of chemical micromotors, including the bubble-recoil mechanism,
which has attracted great attention in the last decades due to its high
efficiency and thrust force, enabling several applications in the fields of
environmental remediation and biomedicine. Bubble-induced motion has been
modeled including three different phenomena: capillarity, bubble growth, and
bubble expulsion. However, most of those models have been suggested
independently based on a single influencing factor (i.e. viscosity), limiting
the understanding of the overall micromotor performance. In this work, we study
the combined influence of medium viscosity, surface tension and fuel
concentration on the switching behavior between different propulsion mechanisms
in the same micromotor. Furthermore, we propose a holistic theoretical model
that explains the three propulsion mechanisms, obtaining good agreement with
the recorded experimental data.
