Enhancing micron-scale transport through swimmer design and geometric constraints

Applied Math Lab, CIMS, 

NYU

I will discuss two interesting problems exploring the role of geometry and shape in low Reynolds number locomotion. The first concerns the optimal design for magnetically actuated micro-swimmers currently being fabricated and studied for biomedical applications. Posing this as an infinite-dimensional optimization problem, we address experimentally realizable morphologies and show that attached payloads have a significant effect on their optimal shape. The second problem deals with how solid obstacles embedded in a fluid affect the locomotion speed of undulating bodies. In a combined numerical and experimental study, we examine the dynamics of the small nematode and model organism C. elegans through a square lattice of micro-pillars. We demonstrate that the interactions with the obstacles allow simple undulators to achieve speeds as much as an order of magnitude greater than their free-swimming values, and that what appears as behavior and sensing can sometimes be explained through simple mechanics.