Effect of body deformability on microswimming.

Area of Science:

• Fluid dynamics
• Biophysics
• Computational physics

Background:

• Microswimmers are essential for understanding biological propulsion.
• The role of body deformability in microswimming remains an active area of research.
• Understanding how body flexibility influences motility is key to designing efficient micro-robots.

Purpose of the Study:

• To investigate whether increased body deformability hinders or promotes the motility of a mechanical microswimming mechanism.
• To elucidate the underlying physical principles governing the relationship between deformability and swimming velocity.
• To identify critical parameters that dictate the effect of body deformability on microswimmer performance.

Main Methods:

• Immersed-boundary-lattice-Boltzmann simulations of a microswimmer composed of deformable beads connected by springs.
• Analytical derivation of the swimmer's velocity based on driving forces and bead deformations.
• Analysis of the influence of deformation frequency modes and spring constants on swimming dynamics.

Main Results:

• The effect of bead deformations on swimming velocity can be either enhancing or reducing, contingent on other system parameters.
• Analytical theory accurately reproduces simulation results for small bead deformations, identifying the driving frequency mode as the primary contributor to velocity.
• Critical values of the spring constant determine whether body deformability is beneficial or detrimental to motion for actively deforming swimmers.

Conclusions:

• Body deformability's impact on microswimming is complex and parameter-dependent.
• A theoretical framework based on forces and small deformations can predict microswimmer velocity.
• The elastic properties of a microswimmer's body play a crucial role in optimizing its motility.