In partial fulfillment of the requirements for the degree of 

Doctor of Philosophy in Quantitative Biosciences

in the School of Physics

Kelimar Diaz Cruz

Defends her thesis:

Non-inertial undulatory locomotion across scales

Wednesday, November 30, 2022

3:00pm Eastern

Krone Engineered Biosciences Building, Children’s Healthcare of Atlanta Seminar Room – EBB 1005

https://gatech.zoom.us/j/96586214860?pwd=citTSHVZRXlVTFliV3ZRT21YZllrUT09 

Meeting ID: 965 8621 4860

Passcode: 113022

Thesis Advisor:

Dr. Daniel I. Goldman

School of Physics

Georgia Institute of Technology

Committee Members:

Dr. Joseph R. Mendelson III

School of Biological Sciences

Georgia Institute of Technology

Dr. Simon Sponberg

School of Physics

Georgia Institute of Technology

Dr. Hang Lu

School of Chemical and Biomolecular Engineering

Georgia Institute of Technology

Dr. David Hu

School of Mechanical Engineering

Georgia Institute of Technology

Abstract:
Locomotion is crucial to behaviors such as predator avoidance, foraging, and mating. In particular, undulatory locomotion is one of the most common forms of locomotion. From microscopic flagellates to swimming fish and slithering snakes, this form of locomotion is a remarkably robust self-propulsion strategy that allows a diversity of organisms to navigate a myriad of environments. While often thought of as exclusive to limbless organisms, a variety of locomotors possessing few to many appendages rely on waves of undulation for locomotion. In inertial regimes, organisms can leverage the forces generated by their body and the surrounding medium's inertia to enhance their locomotion (e.g., coast or glide). On the other hand, in non-inertial regimes self-propulsion is dominated by damping (viscous or frictional), and thus the ability for organisms to generate motion is dependent on the sequence of internal shape changes. In this thesis, we study a variety of undulating systems that locomote in highly damped regimes. We perform studies on systems ranging from zero to many appendages. Specifically, we focus on four distinct undulatory systems: 1) Cae. elegans, 2) quadriflagellate algae (bearing four flagella), 3) centipedes on terrestrial environments, and 4) centipedes on fluid environments. For each of these systems, we study how the coordination of their many degrees of freedom leads to specific locomotive behaviors. Further, we propose hypotheses for the observed behaviors in the context of each of these system's ecology.