Electromechanical modeling and experimental validation of an origami-structured triboelectric vibration energy harvester

This study presents a novel electromechanical model and its experimental validation for an origami-structured triboelectric energy harvester (OTEH) designed to scavenge kinetic energy from vibration. OTEHs are recognized for their enhanced electrical output due to increased contact areas from stacked structures, but their electromechanical modeling remains largely unexplored due to geometric complexity. Furthermore, few studies have investigated the use of OTEHs for harvesting vibration energy. To address these gaps, we developed an electromechanical model specifically tailored for vibration energy harvesting using OTEHs. The model integrates an electrical model for triangular non-parallel contact surfaces with a lumped-parameter mechanical model, incorporating origami geometric parameters for broad applicability. We experimentally validated the model using a bellow-origami-structured triboelectric energy harvester (BOTEH) designed for vibration energy harvesting. Benefiting from axial elasticity and a guiding rod, the BOTEH structure can be excited by harmonic base vibration, enabling a systematic investigation of its vibration-energy-harvesting potential. The model, validated through time-domain and frequency-domain voltage and displacement responses under various vibratory conditions, accurately predicts the BOTEH's dynamic behavior. Additionally, under base forcing vibration, the BOTEH demonstrated practical utility by triggering an Internet-of-Things (IoT) temperature sensor and illuminating 24 LEDs, achieving a maximum output power of 119 μW at 6.6 Hz and 0.8 g with an 80 MΩ external resistor.