Layer by layer assembly is a multilayer film or nanostructural material processing method with the advantages of simplicity, universality, etc. Hence, layer-by-layer assembly has been applied to design graphene-based self-healing materials. For example, Sun J et al. prepared a healable film via layer-by-layer assembly of poly (acrylic acid) with complexes of branched poly grafted with ferrocene and RGO nanosheets modified with β-cyclodextrin , whose self-healing performance involves an interesting oxidation-reduction process. Besides, Ge L et al. fabricated the bPEI/(PAA-GE) self-healing multilayer polyelectrolyte film based on branched poly (ethyleneimine) , poly (acrylic acid) and graphene by layer-by-layer assembly technique, which not only shows excellent self-healing ability at high humidity, but also possesses good electrical conductivity. Moreover, Li Y et al. proposed a 5S film of the first self-healing, mechanically strong and stretchable, self-activated pressure-sensing device nanostructure, including conductive layer , piezoelectric layer , and healing substrate (PDMAA) . In addition, Fig. 3B–(b, c, d, e) shows the microscopic structures of the boundary between the two functional layers, and the electrode layer alone. And the self-healing process in Fig. 3B–g shows that the 5S film was cut into two pieces, then brought back into contact and healed at room temperatures in air.