Two‐Dimensional Framework Materials as Building Blocks for Next‐Generation Intelligent Biointerfaces

The convergence of neural interfaces, wearable bioelectronics, and human‐machine interaction is driving intelligent biointerfaces capable of sensing and responding to neural, physiological, and biomechanical signals. Realizing this vision demands a substantial advance in sensing and actuation hardware, which remains constrained by trade‐offs in conventional bulk materials. This review proposes that two‐dimensional framework materials, encompassing intrinsic 2D crystals, heterostructures, composites, and low‐dimensional architectures, provide a transformative platform to overcome these barriers. The application scope is organized into five categories: implantable neural interfaces, non‐invasive neural interfaces, physiological sensing, wearable human‐machine interfaces, and soft actuation or haptic feedback. We establish a three‐tier architecture. First, we catalog the requirements of piezoresistive, piezoelectric, capacitive, electromagnetic, electrostatic, and electrothermal sensors and actuators, identifying performance bottlenecks in bulk materials. Second, we trace these ceilings to microscopic origins: continuous electronic density of states, strong dielectric screening, coupled elastic‐thermal phonon transport, and weakly tunable electron‐phonon coupling that lock sensitivity, compliance, energy efficiency, and thermal safety into trade‐offs. Third, we show how quantum confinement, attenuated screening, and broken symmetry in 2D materials decouple these constraints. We conclude by outlining a co‐design strategy integrating heavy‐element doping, symmetry engineering, interfacial design, and coupling phenomena to tailor 2D materials for next‐generation intelligent biointerfaces.