Self‐Powered Mechanical Nanofluidic Generators Based on Gradient Charge‐Modified Sustainable Wood‐Derived Nanochannels

Abstract The growing demand for self‐powered technology in portable and wearable electronics has spurred significant advancements in energy harvesting systems. However, conventional mechanical generators based on triboelectric and piezoelectric effects are limited by short discharge durations, despite achieving high output potentials. Here, a mechanical nanofluidic generator (MNG) is reported with gradient charge‐modified nanochannels, designed for mechanical energy harvesting. The MNG features highly aligned nanochannels with engineered surface charges, enabling a peak output voltage of 10.58 ± 1.29 V and a prolonged energy release time of 675.80 ± 112.08 s, with orders of magnitude longer than traditional generators that normally discharge in milliseconds to microseconds. This superior performance is attributed to the synergistic effects of gradient surface charge modification and enhanced interactions between transport ions and surface charges. This performance is attributed to the synergistic effects of surface charge gradients and strengthened ion–surface interactions, underscoring the MNG's potential for next‐generation self‐powered systems.