Figure 2: Measured force–shear displacement curves.

Typical measured force–shear displacement curves for loading (red solid line) and unloading (blue dashed line) in ambient conditions at temperatures (a) 22 °C, (b) 50 °C and (c) 119 °C. The shaded area in b between the entire region (III) loading curve and the unloading curve is the energy dissipated in sliding and retraction. This energy dissipation can be normalized by the region (III) width, w, and the sample width B to find the dissipative energy (see more below). (d) The time traces of the shearing distance (black dashed line) and the shear force (red solid line) at 22 °C. (e) Optical images of the sheared mesa (left) and retracted mesa (right). Scale bar, 4 μm.