An Ultrahigh‐Resolution, Cross‐Scale Triboelectric Sensor for Civil Infrastructure Health Monitoring

ABSTRACT Monitoring the progressive, cross‐scale evolution of concrete surface cracks at known critical locations, from micron‐level initiation to centimeter‐level propagation, is imperative for safeguarding civil infrastructure. While triboelectric nanogenerators (TENGs) offer transformative potential for structural health monitoring, their spatial resolution remains fundamentally dictated by physical electrode dimensions, precluding true cross‐scale tracking. Herein, an ultra‐high resolution triboelectric displacement sensor (URTDS) is proposed to break this fundamental physical bottleneck. The core innovation lies in a single‐electrode asymmetric multi‐phase architecture that utilizes a fractional spatial phase shift to fundamentally decouple encoding resolution from physical electrode width. Synergistically coupled with the displacement amplification mechanism, the URTDS seamlessly translates micro‐linear deformations into high‐density rotational electrical signals. The unique design enables the URTDS to achieve an extraordinary spatial resolution of 3.687 µm, across an extensive centimeter‐level measurement range, maintaining a deviation below 4%. Beyond this, the URTDS exhibits exceptional robustness against environmental disturbance and negligible signal degradation over 100,000 continuous cycles. Finally, the potential of URTDS for capturing microcrack propagation is highlighted through a real‐time monitoring and early warning system. This work establishes a universal design paradigm for high‐precision triboelectric sensing, paving the way for self‐powered solution for targeted full‐lifespan monitoring of civil infrastructure at critical locations.