Kirigami Energy Harvesters: On Exploiting Multi-Modal and Multidirectional Vibration in Aerospace Structures

This study presents a novel vibration energy harvester that integrates kirigami-inspired three-dimensional (3D) metastructures with piezoelectric materials, to improve energy capture efficiency in broadband and multidirectional vibrational environments. Conventional piezoelectric energy harvesters (PEHs) often suffer from narrow resonant frequency bands and limited directional sensitivity, making them less effective in real-world dynamic conditions in aerospace structures. In aerospace systems, where minimising weight and enabling autonomous operation is paramount, such limitations hinder the deployment of long-term, battery-free sensing solutions. To solve these challenges, we propose a kirigami-based unit cell design strategy, which was simulated for geometry generation and analysed using finite element methods for static and dynamic performance assessment. The results reveal significant improvements in displacement flexibility, operational frequency bandwidth, and voltage output. These findings highlight the potential of kirigami-enhanced PEHs as integrated, passive power sources for aerospace applications such as structural health monitoring and in-flight sensor networks. This work also demonstrates the broader applicability such as wearable electronics, autonomous sensing, and environmental monitoring.