Testing non reciprocal motion of a swimming flexible small robot with single actuation

The fluid dynamics in a microscale system is characterised by a low Reynolds number environment, which means that viscous forces dominate over inertial forces in a time-independent flow. To propel a swimming microrobot in that environment, a non reciprocal motion is needed, being the paramount example the known as travelling wave motion. The typical ways to excite a flexible structure with a travelling wave imply distributed actuation along it. In this paper, several ways are tested to generate a travelling wave in a small flexible microrobot with a single point actuation. By using computer vision, an experimental set up is developed to track the movement of the robot and identify what kind of wave is carried out.