A Fluid‐Induced Vibration Energy Harvester Based on Metasurfaces

Fluid‐induced vibration (FIV) energy harvesting captures kinetic energy from flowing fluids, converting it into electrical power and showing particular promise for low‐speed wind applications. This study presents a metasurface‐enhanced FIV harvester combined with a branching beam structure to improve energy conversion efficiency. The branching beam adjusts the system's natural frequency, while metasurfaces with circular, square, and striped dimple arrays modify the bluff body's hydrodynamic behavior. Wind tunnel experiments used cylindrical and square cross‐section bluff bodies at flow velocities of 1–6 m s −1 . Results show the circular‐dimple metasurface significantly enhances performance: above 3 m s −1 , it yields output voltages 32%–70.56% higher than conventional harvesters, reaching 1.491 V at 4 m s −1 versus 0.875 V for a smooth cylinder. Maximum output power reaches 2.22 μW, a 188% increase. The striped metasurface improves voltage output by 10%–15%. For square cylinders, the circular‐pit metasurface achieves 4.88 μW at 5 m s −1 , nearly double the conventional output. The branching beam effectively tunes resonant frequency while maintaining piezoelectric efficiency. These findings validate the synergistic use of metasurfaces and structural frequency control for advancing FIV energy harvesting in low‐velocity flows.