Figure 2 : Force-dipole stiffness distribution.

From: Physical limits to biomechanical sensing in disordered fibre networks

Figure 2

(a,b) Examples of local stiffness sensing by force dipoles. Modelled deformation under stress from a local force dipole of length d15 μm (green arrows) of (a) experimental collagen network and (b) RGG network. Magnitude of fibre deformations indicated by colour (small deformations, blue; large deformations, red). (c,d) Distribution of local stiffnesses kloc defined as the linear response of local deformation to a force dipole of length d15 μm for (c) collagen network and (d) RGG network. Geometric s.d. of local stiffness σloc indicated by bars (actual distribution, black; estimated distribution assuming strong locality, red; estimated distribution assuming weak locality, orange; see Supplementary Figs for details). Insets show stiffness loss Δ, defined as the relative change in local stiffness kloc upon perturbing a network by removing a single fibre, versus distance R of centre of removed fibre from the probe centre. For collagen, probe length d<10 μm and removed fibre length , and for RGG, probe length and removed fibre length . Error bars, defined as the s.d. of each data point divided by the square root of the number of samples averaged, are smaller than the size of data points. Dashed lines show asymptotic scaling from continuum theory, which predicts for (see Supplementary Figs for details).