Search

With the refinement and miniaturization of integrated electronic devices, the requirements for stable operating temperature and antielectromagnetic interference are increasingly high. However, most of the current materials necessitate to develop the intelligent self‐adaptive regulation in response to external field stimuli to gratify the stipulations of different operating environments. Herein, cuttlefish‐inspired smart liquid metal based‐liquid crystal elastomer (LGN‐LCE) dual‐functional material enabling self‐adaptive electromagnetic wave interference shielding and thermal management is presented. Liquid crystal elastomer matrix endows the LGN‐LCE dynamic self‐morphing properties under thermal activation, which leads to the liquid metal network with tunable thermal/electrical conduction. The thermal conductivity of LGN‐LCE can be increased to 10.3 W m−1 K−1 with the rise of surrounding temperature, while the electrical conductivity of LGN‐LCE can be enhanced to 4.3 × 105 S m−1. Such promoted electrical conductivity helps strengthen electromagnetic interference (EMI) shielding performance of LGN‐LCE, and the minimum EMI shielding effectiveness of LGN‐LCE can be improved from 48 to 62 dB within the X‐band. This work may not only pave a new way to rationally design a self‐adaptive EMI shielding and thermal management systems, but also show good prospects for practical applications, including thermal management materials, EMI materials, flexible electronic materials, smart materials, artificial intelligence systems, biomedical, and aerospace applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bottom-up strategy for producing isotropic liquid metal network in polymer. • Liquid metal composites can be applied for high-performance thermal management. • The approach is applicable for various liquid metal filler of different viscosity. • Thermal conductivity was controlled by volume fraction of filler and size of TPE. • A high intrinsic thermal conductivity (up to 32.71 W/mK) was obtained. This work presents a bottom-up approach to construct an isotropic network of liquid metal in polymer, and such generated isotropic liquid metal network brings large enhancement on the thermal and electrical conductivity of the composite for 3D thermal management. The building blocks are composed of polymer particles coated with liquid metal. The liquid metal starts to flow and fill the gaps between the polymer particles, and fuses with each other to assemble into a continuous liquid metal network in the polymer matrix under the mechanical load during heating. The continuous filler network provides effective paths for thermal and electrical conduction, and thus enhances the thermal and electrical conductivity of the composites. Using biphasic copper-eutectic gallium indium as the filler, we generated polymer composites with thermal conductivity as high as 32.71 W/m·K (90 vol%; under compression) and electrical conductivity up to 1.18 × 106 S/m. Moreover, the measurement of the in-plane and cross-plane thermal diffusivity reveals the isotropic enhancement of thermal conductivity in such composites, which may help expand the potential application of these composites in 3D thermal management, flexible electronics, energy conversion and soft robotics. [ABSTRACT FROM AUTHOR]