Development of a Novel Combined Wind-Rain Piezoelectric Energy Harvester

Aiming at the unstable power output of single-source piezoelectric energy harvesters for ecological monitoring in bird nature reserves, this work develops a novel combined wind-rain piezoelectric energy harvester and establishes a complete numerical modeling framework. The proposed device integrates a snowflake-shaped bluff body for broadband vortex-induced wind energy capture and a self-tilting water container for raindrop gravitational potential energy collection, with both excitation sources equipped with independent piezoelectric cantilevers that share a unified passive parallel-synchronized switch harvesting on inductor (P-SSHI) interface circuit for coordinated energy conversion of two ambient energy sources. A full set of closed-loop theoretical formulas covering rain potential energy, vortex-induced aerodynamic excitation, electromechanical coupling, and LC-resonance-based voltage inversion is derived. Static finite element analysis, Multisim circuit simulation, and oscilloscope-based bench-scale experiments are implemented to evaluate structural deformation, stress distribution, output voltage, impedance-matched power, and steady-state load performance. Simulation and experimental results validate the rationality of the structural scheme and mathematical model. All validations are performed under laboratory-simulated conditions, and long-term field meteorological tests are reserved for future investigations. The compact low-noise proof-of-concept prototype shows application potential for field monitoring nodes, and the established modeling framework provides design references for multi-source kinetic-energy harvesters.