Hybrid Spring‐Coupled Broadband Energy Harvester Integrated with CuSCN Functionalized Triboelectric Vibration Sensor for Self‐Sustainable Vehicular IoTs

Energy harvesting from low‐acceleration, broadband vehicular vibrations remains challenging due to low‐amplitude and random frequency nature of such excitations, often poorly matched to conventional narrowband spring‐mass designs. Herein, a hybrid spring‐coupled broadband vehicle vibration energy harvesting(VEH) and triboelectric vibration sensing(TVS) module is proposed that exploits coupled mechanical resonance and frequency disparity between spring elements to achieve vibration amplification under low‐amplitude and wide‐frequency excitations. VEH combines the motion dynamics of high stiffness 3D printed multiturn wave spring and low‐stiffness metallic disc spring, enabling simultaneous vibration of coil and magnet for enhanced mechanoelectrical conversion over braoder frequency (1–30 Hz). Simulations and experiments confirmed that the dual‐spring coupling yields superior mechanoelectrical conversion (above 50%) under 0.5 g with peak and average powers of 260 mW(5.72 mW/cm 3 ) and 88 mW(1.89 mW/cm 3 ). Furthermore, lightweight spiral spring‐integration with PAN‐CuSCN composite nanofiber provides self‐powered vibration sensing through its pronounced tribonegative response as compared to the pristine nanofiber, enabling accurate road classification(>95%) and speed classification (84.1%) with minimum detection upto 0.075g. This dual‐functional module combining broadband energy harvesting, self‐powered vibration sensing with miniaturized PCB, integrated sensors and BLE allows continuous operation in realistic vehicular vibration environments, establishing a reliable framework for self‐sustainable vehicular environmental monitoring systems.