Kinematics of the most efficient cilium

Abstract

In a variety of biological processes, eukaryotic cells use cilia to transport flow. Although cilia have a remarkably conserved internal molecular structure, experimental observations report very diverse kinematics. To address this diversity, we determine numerically the kinematics and energetics of the most efficient cilium. Specifically, we compute the time-periodic deformation of a wall-bound elastic filament leading to transport of a surrounding fluid at minimum energetic cost, where the cost is taken to be the positive work done by all internal molecular motors. The optimal kinematics are found to strongly depend on the cilium bending rigidity through a single dimensionless number, the Sperm number, and closely resemble the two-stroke ciliary beating pattern observed experimentally.

4 pages, 5 figures

References in corpus (1)

• The hydrodynamics of swimming microorganisms

Cited by in corpus (6)

• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Efficiency limits of the three-sphere swimmer
• Optimal propulsive flapping in Stokes flows
• The other optimal Stokes drag profile
• Cilia beating patterns are not hydrodynamically optimal
• Travelling waves are hydrodynamically optimal for long-wavelength flagella