Figure 1.

Mechanical assays under SHG microscope. (a) Side view of the setup, showing the skin sample attached to the traction device by use of metallic jaws. Immersion gel prevents skin dehydration and ensures optical contact with the objective lens. (b) Nominal stress/stretch curve obtained for an old WT mouse, showing the parameters used to quantify the macroscopic mechanical response. Blue solid curve: experimental data; red dashed curve: linear fitting providing the tangent modulus. (c) Nominal stress/time curve for the same sample showing series of short relaxations when the stretching is stopped during SHG imaging. Inset: zoomed relaxation, showing fitting with Eq. (1) (red dashed curve).