(a) Temperature dependence of the electrical conductivity and thermal diffusivity of the CNT adhesive from −196 to 1,000 °C by testing the Cu/CNT/Cu structure (cf. Supplementary Fig. 15). (b) Correlation between the electrical conductivity, thermal diffusivity and the mechanical adhesion enhancements with increasing temperature. (c) Stability of the CNT adhesive reflected by the electrical current (at 1 mV) going through the Cu/CNT/Cu structure under about 400 repeated temperature transition cycles. Inset shows an enlarged view of the heating and cooling transitions from 57th to 63rd cycles: a (25 °C)→b (−196 °C)→c (25 °C)→d (−196 °C)→e (25 °C)→f (−196 °C)→g (−196 °C)→h (1,000 °C)→i (25 °C)→j (1,000 °C)→k (25 °C)→l (1,000 °C)→m (25 °C)→n (1,000 °C).