The word "Rizeh" is a Persian word that means "tiny". Rizeh is a vibration based very small robot. It is driven by two vibrators of cell phones. This makes the robot very low cost to build and implement. The robot is able to perform linear and circular motions as two basic motions in mobile robots. Control mechanism of the robot employs internal PWM of micro-controller to control vibrators. Some techniques are applied to minimize electronic control board of the robot which is a very crucial in building up a small robot.
As a standard task in mobile robots, line following task is selected to test Rizeh. In this test the robot follows a black 5mm width line on a white background. The path includes some curves, lines and cornets as it is shown in figure. The robot is able to successfully follow the line.