A robust hybrid generator for harvesting vehicle suspension vibration energy from random road excitation

Existing energy harvesters are mostly designed into the electromagnetic shock absorbers to replace the original dampers in automotive suspension systems, possibly deteriorating sprung mass acceleration when the energy harvesters are in trouble. Therefore, this study proposed a hybrid generator based on the sliding-mode triboelectric nanogenerator (S-TENG) and electromagnetic generator (EMG) to harvest the suspension vibration energy without replacing the original damper and deteriorating sprung mass acceleration. First, the patterned polyimide (PI) films were prepared to solve the challenge of the poor durability of the S-TENG due to material wear. The results showed that the wear mass loss of PI film diminished with the decrease of pillar pitch, and the wear mass loss of P2 film was only 37% of that of the smooth one. Furthermore, whether the patterned surface could improve the electrical output of the S-TENG depended on the pattern parameters, which was a departure from the common view that any pattern could enhance triboelectrification. In this paper, P2 was the optimal textural parameter for improving the durability and electrical output of the S-TENG, which could provide a texture design reference for the S-TENG. Second, the hybrid generator charged a 4.7 μF capacitor to 18.05 V in 60 s, and the contribution ratio of charging voltage of the S-TENG component increased with extended charging time. Finally, the hybrid generator moved together with the original shock absorber without a noticeable impact on sprung mass acceleration, which can make the accelerometer self-powered at different random road excitations.