Research / 2020 / Article / Fig 2

Research Article

Mg-Based Micromotors with Motion Responsive to Dual Stimuli

Figure 2

The motion responsiveness of the as-prepared Mg-based micromotors to temperature and H2O2. (a) Time-lapse microscope images of the Mg-based micromotor moving in aqueous solutions. Scale bar: 100 μm. All systems contain 0.5 M NaHCO3 and 5 wt% PVP, and the color of the trajectory points represents the instantaneous speed of the Mg-based micromotor. (b) The corresponding angular velocities of the Mg-based micromotor in the four motion states of (a). The clockwise is specified as the positive direction. The inset is the schematic of force analysis for the Mg-based micromotor. The bubble breaks out of the micromotor and gives it a recoil ( and ) that contributes forces ( and ) for the motor rotation and translational motion toward the opposite direction of bubble generation, respectively. and are the angles between the directions of the centroid connection line and ; and are the vertical distances between the center of mass of the Mg-based micromotor and and .