Braiding Dynamics in Semiflexible Filament Bundles under Oscillatory Forcing.

Area of Science:

• Physics
• Materials Science
• Soft Matter Physics

Background:

• Semiflexible filament bundles exhibit complex behavior under mechanical stress.
• Topological defects, such as braids, can form in these systems.
• Understanding nonequilibrium defect formation is crucial for predicting material properties.

Purpose of the Study:

• To investigate the nonequilibrium production of topological defects (braids) in semiflexible filament bundles.
• To analyze the dynamics of braid formation and proliferation under cyclic compression and tension.
• To study the creep behavior of braided bundles under sustained tension.

Main Methods:

• Simulating cyclic compression and tension on filament bundles.
• Analyzing thermally activated pair production of braid/anti-braid pairs.
• Investigating slow bundle extension under fixed force conditions.

Main Results:

• Compression cycles promote the production of braid/anti-braid pairs.
• Alternating compression and extension lead to braid proliferation, exceeding equilibrium densities.
• Braided bundles exhibit nonmonotonic creep under tension due to braid deformation and motion.

Conclusions:

• Nonequilibrium processes significantly enhance topological defect formation in filament bundles.
• The observed creep behavior provides insights into the mechanical response of braided structures.
• Findings suggest potential experimental avenues for controlling defect density and understanding bundle mechanics.