Design strategies and innovations in compliant mechanism-based energy harvesting: A comprehensive review

Abstract

The growing demand for sustainable, portable, and self-powered devices has accelerated research in vibration energy harvesting (VEH) technologies. VEH provides an efficient means of converting ambient mechanical vibrations into electrical energy, offering a viable power source for low-energy electronic systems, especially in remote or maintenance-free environments. Among various design paradigms, compliant mechanisms have emerged as a promising approach to enhance VEH performance. By exploiting structural flexibility, these mechanisms enable vibration amplification, motion rectification, and reduced mechanical losses, thereby improving energy conversion efficiency even under low-frequency excitations commonly encountered in ambient settings. This comprehensive review focuses on design strategies and innovations in compliant mechanism-based VEH systems. It systematically discusses recent developments across different transduction mechanisms, including piezoelectric, electromagnetic, triboelectric, and hybrid systems integrated with compliant structures. Key design concepts, including resonance tuning, multi-modal excitation, motion amplification, and structural optimization, are analyzed in detail. Furthermore, the review identifies emerging trends in integrating compliant VEH designs with advanced applications, including structural health monitoring, wearable electronics, biomedical implants, and Internet of Things (IoT) devices. By synthesizing recent innovations and highlighting design-oriented insights, this review provides a unified understanding of compliant mechanism-based VEH systems and outlines future directions for achieving higher efficiency, adaptability, and scalability in next-generation energy harvesters.