(a) Temperature dependence of the adhesion force for the CNT dry adhesive. Inset shows the enhancement factor versus temperature. (b) SEM images for the residual CNTs on the detached copper surface after testing at 1,000 °C, showing the temperature-induced screw-like nano-interlocking (scale bar, 2 μm). (c) Calculated temperature-dependence of the enhancement factor (red, blue and orange circles) (cf. equation (1)) along with the corresponding experimental data (black dots) for comparison. (d) Verification of the nano-interlocking model for different target surfaces. Each of the adhesion strength data points was averaged from five samples measured under the same ex situ thermal control conductions.