Graphene‐reinforced polymer composites with high thermal conductivity show attractive prospects as thermal transfer materials in many applications such as intelligent robotic skin. However, for the most reported composites, precise control of the thermal conductivity is not easily achieved, and the improvement efficiency is usually low. To effectively control the 3D thermal conductivity of graphene‐reinforced polymer nanocomposites, a hyperelastic double‐continuous network of graphene and sponge is developed. The structure (orientation, density) and thermal conductivity (in‐plane, cross‐plane) of the resulting composites can be effectively controlled by adjusting the preparation and deformation parameters (unidirectional, multidirectional) of the network. Based on the experimental and theoretical simulation results, the thermal conduction mechanism is summarized as a two‐stage transmission of phonons. The in‐plane thermal conductivity increases from 0.175 to 1.68 W m−1 K−1 when the directional compression ratio increases from 0% to 95%, and the corresponding enhancement efficiency exceeds 300. The 3D thermal conductivity reaches a maximum of 2.19 W m−1 K−1 when the compression ratio is 70% in three directions, and the graphene content is 4.82 wt%. Moreover, the thermal conduction network can be largely prepared by power‐driven roller equipment, making the composite an ideal candidate for sensitive robotic skin for temperature detection.

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Aggregation-induced emission (AIE) materials present unique solid-state fluorescence. However, there remains a challenge in the switching of fluorescence quenching/emitting of AIE materials, limiting the application in information encryption. Herein, we report a composite of tetraphenylethylene@graphene oxide (TPE@GO) with switchable microstructure and fluorescence. We choose GO as a fluorescence quencher to control the fluorescence of TPE by controlling the aggregation structure. First, TPE coating with an average thickness of about 31 nm was deposited at the GO layer surface, which is the critical thickness at which the fluorescence can be largely quenched because of the fluorescence resonance energy transfer. After spraying a mixed solvent (good and poor solvents of TPE) on TPE@GO, a blue fluorescence of TPE was emitted during the drying process. During the treatment of mixed solvents, the planar TPE coating was dissolved in THF first and then the TPE molecules aggregated into nanoparticles (an average diameter of 65 nm) in H 2 O during the volatilization of THF. We found that the fluorescence switching of the composite is closely related to the microstructural change of TPE between planar and granular structures, which can make the upper TPE molecules in and out of the effective quenching region of GO. This composite, along with the treatment method, was used as an invisible ink in repeated information encryption and decryption. Our work not only provides a simple strategy to switch the fluorescence of solid-state fluorescent materials but also demonstrates the potential for obtaining diverse material structures through compound solvent treatment.