Curvature-Mediated Forces on Elastic Inclusions in Fluid Interfaces

Area of Science:

• Soft matter physics
• Fluid dynamics
• Materials science

Background:

• Heterogeneous fluid interfaces often contain 2D solid domains.
• The mechanical response of rigid inclusions to interfacial curvature is known.
• The behavior of elastic inclusions in curved interfaces is largely unexplored.

Purpose of the Study:

• Investigate the influence of elasticity on solid inclusions in curved fluid interfaces.
• Characterize the curvature-driven motion of deformable solids.
• Explore the distinct behaviors of inclusions based on size and stiffness.

Main Methods:

• Theoretical calculations of forces on solid inclusions.
• Analysis of inclusion behavior in bending- and stretching-limited regimes.
• Modeling deformable solids within a variable Gaussian curvature interface.

Main Results:

• Small, stiff inclusions move up Gaussian curvature gradients (bending-limited).
• Larger, softer inclusions move down squared Gaussian curvature gradients (stretching-limited).
• Calculated forces collapse onto a universal curve across regimes.

Conclusions:

• Inclusion size and stiffness dictate motion direction in curved interfaces.
• Elasticity introduces distinct behaviors compared to rigid inclusions.
• Predictions are made for deformable solid motion in model interfaces.