Triboelectric Nanogenerator Metamaterials for Joint Vibration Mitigation and Self-Powered Structure Monitoring

Abstract

A metamaterial-inspired triboelectric nanogenerator (META-TENG) is proposed, targeted to simultaneously realize vibration suppression and energy harvesting. The compact META-TENG can generate local resonant phenomenon and vigorously sink the incident vibration energy at the low-frequency band. A planar spring is developed, which guarantees low-frequency resonance and sufficient triboelectric contact surface within a small-scale device. The band-gap property of the proposed metamaterial is calculated using the finite element method, which fits well with the experimental measurement result. For the fabrication of TENG, fluorinated ethylene propylene (FEP) film is selected as the negative triboelectric material, and Ecoflex is chosen as the positive triboelectric material. It is found that the introduction of multi-walled carbon nanotubes (MWNT) into Ecoflex is favorable for the enhancement of META-TENG’s output performance, with almost three times improvement of output voltage. The charge density of the TENG can reach up to 453.1 µC/m 2 under 5 N sinuous excitation. The periodic META-TENG configuration also exhibits satisfying performance of vibration suppression. For an aluminum plate integrating four META-TENGs, the vibration amplitude of the structure can decrease by up to 87%. The harvested energy from the META-TENG array enables an accelerometer and Bluetooth module working in wireless mode, making the whole system achieve self-powered vibration monitoring.

Keywords: Triboelectric Nanogenerator, vibration mitigation, self-powered system, local resonant metamaterials, multifunctional structure