Batteries provide electrical energy to the motor, which rotates the rotor at high speed. When the rotor turns, it causes the robot to vibrate from side to side and up and down. The vibrations make the brushes jump on the surface and land again with high frequency. As the large brush lands after each vibration, its bristles bend, pushing the entire robot slightly, in the same way that a brush is angled. When the brush jumps again, the bristles straighten. This process is repeated continuously, causing the brush robot to move forward.