Students: Zemichael Gebeyehu

Project: Examining Fluid-Mediated Self-Organization of Two Robotic Fish

Poster: Vertical (PDF) | Horizontal (PDF)

Institution: Lehigh University

Major: Mechanical Engineering & Mechanics

Advisor: Keith Moored


Self-organizing behavior in fish schools is a captivating natural phenomenon. However, our understanding of how these hydrodynamic interactions occur is limited. There are various predictions that explain how synchronization and collective locomotion are influenced by the energetics and stable equilibria of the system. In order to further understand the two-dimensional stability of biological swimmers such as tuna fish and how hydrodynamic forces drive the schooling, a new design of two robotic fish (tunabots) has been implemented to mimic the shape of an actual tuna fish. During the experiments, both in-phase and out-phase synchronization of the flapping motion is being explored and translational motion of each tunabot is recorded by utilizing an inertial measurement unit and laser distance measurements. Each tunabot is controlled by a microcontroller that feeds data back to a host computer via Wi-Fi. To mitigate accumulated error of synchronization, an absolute motor encoder is being used, targeting flapping frequencies ranging from 3 Hz to 5 Hz. Understanding the passive self-organization of these two robotic fish helps us to understand the schooling of biological swimmers and future designs of bio-inspired vehicles.

Zemichael Gebeyehu

About Zemichael Gebeyehu

Zemichael Gebeyehu, a sophomore (with junior standing) studying mechanical engineering with a double minor in aerospace and electrical engineering. Zemichael is an undergraduate research assistant at Professor Keith Moored’s lab (Unsteady Flow Laboratory). Since his first year at Lehigh University, Zemichael worked on worked on the design, testing, optimization, and integration of autorotating UAVs by utilizing vertical and closed return wind tunnel testing. Currently he is working on the development of robotic tuna fish to study the fluid meditated forces and their effects on fish schooling, swimming performance, and efficiency. Outside of coursework and research, Zemichael is a co-founder and president of Lehigh University Space Initiative, a Student for Exploration & Development of Space (SEDS USA) chapter that promotes spaceflight and astronautics through projects ranging from Mars rovers to CubeSats. He also serves as a team lead for Lehigh Underwater Robotics (LUR), a student research team developing an Autonomous Underwater Vehicle for Robosub 2022 international competition. Additionally, Zemichael is an aerodynamics design lead for Lehigh Formula SAE team, working on the design and development of wings (front and rear), nosecone, and side-pod. He is also a member of the African Student Association (ASA), National Society of Black Engineers (NSBE), Lehigh Aerospace Club, and International Voices.