2003/12/18 by D. A. Head, David Head, Alex J. Levine +2 · 2 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Advanced Fluorescence Microscopy Techniques #Cellular Mechanics and Interactions #Force Microscopy Techniques and Applications
paper · doi:10.1103/physreve.68.061907
openalex publication_date 2003/12/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Semiflexible polymers such as filamentous actin (F-actin) play a vital role in the mechanical behavior of cells, yet the basic properties of cross-linked F-actin networks remain poorly understood. To address this issue, we have performed numerical studies of the linear response of homogeneous and isotropic two-dimensional networks subject to an applied strain at zero temperature. The elastic moduli are found to vanish for network densities at a rigidity percolation threshold. For higher densities, two regimes are observed: one in which the deformation is predominately affine and the filaments stretch and compress; and a second in which bending modes dominate. We identify a dimensionless scalar quantity, being a combination of the material length scales, that specifies to which regime a given network belongs. A scaling argument is presented that approximately agrees with this crossover variable. By a direct geometric measure, we also confirm that the degree of affinity under strain correlates with the distinct elastic regimes. We discuss the implications of our findings and suggest possible directions for future investigations.