A self-healing conductive ink.

The mechanical durability of conductive materials affects the performance and lifetimes of devices ranging from electrical circuits to battery electrode materials. Mismatches in thermal expansion coeffi cient, Young’s modulus, and Poisson’s ratio between the conductive materials and packaging materials in integrated circuits lead to delaminations and fractures both within conductive pathways and at interconnects. [ 1 , 2 ] Fatigue causes microcracks that can lead to channeling, debonding, and failure. [ 3–5 ] The repeated lithiation and delithiation of battery electrode materials upon charging and discharging contribute to decreased capacitance due to a loss of interparticle connectivity and conductivity. [ 6–9 ] Numerous approaches have been used to design circuits and materials to prevent mechanical failure, but only a few have focused on restoring conductivity after mechanical damage. [ 10–15 ]