Anisotropic 3D‐Printed Carbon Fiber‐Reinforced Liquid Metal Elastomer for Synergistic Enhancement of Electrical Conductivity, Thermal Performance, and Leakage Resistance

Developing multifunctional composites with high electrical/thermal conductivity and excellent flexibility remains a critical challenge for flexible electronics and thermal management systems. While liquid metal elastomers offer intrinsic softness and conductivity, their real‐world application is hindered by the trade‐off between outstanding dual conductivity (electrical and thermal) and leakage resistance. To tackle this issue, high‐stability carbon fiber‐reinforced liquid metal elastomer (CFLME) is fabricated via an integrated method: Ni plating on carbon fiber to enhance reactive wetting with liquid metal, followed by composite formation with elastomer and 3D printing for directional fiber alignment, yielding anisotropic CFLME. Such anisotropic architecture enables efficient conductive pathways along fiber axes, reducing the electrical percolation threshold to 25%, achieving a high electrical conductivity of 3.44 × 10⁵ S/m, and a thermal conductivity of 7.26 W/(m∙K). The fiber network securely locks liquid metal, enabling zero leakage under 400% strain, 1000‐cycle stretching, or 833 kPa compression. For practical applications, CFLME exhibits exceptional electromagnetic shielding (93.74 dB), high‐sensitivity biosensing with an 82.62 dB signal‐to‐noise ratio, and efficient thermal management (16 °C reduction vs liquid metal elastomer). This work demonstrates a dual‐innovation strategy of structural design and interfacial regulation, providing a robust solution for flexible electronics and thermal management applications with balanced performance.