The Need

Many vibration-based energy harvesting systems are limited by narrow operational frequency bands, making them inefficient for environments where excitation frequencies drift, such as in bridges, machinery, or vehicles. Current solutions often sacrifice energy density to broaden bandwidth. A more efficient, self-tuning piezoelectric energy harvester that maintains high energy output across a wide frequency range would enable more reliable and self-sustained sensor systems in dynamic environments.

The Technology

OSU engineers have developed a novel energy harvesting system that integrates a piezoelectric cantilever beam with a piecewise-linear (PWL) stopper and a simple feedback control algorithm. The system automatically adjusts the gap between the beam and stopper using a microcontroller-driven actuator based on real-time voltage feedback. This dynamic control modifies the beam’s resonant frequency to match shifting excitation conditions, improving energy output across a broader frequency spectrum. Experimental validation demonstrates a 37% performance improvement over linear systems and robust operation during rapid frequency shifts.

Commercial Applications

• Powering wireless sensor networks in industrial machinery.
• Energy harvesting in transportation systems (e.g., railways, automotive).
• Wearable or implantable biomedical devices.
• Structural health monitoring in bridges and civil infrastructure.
• Remote environmental monitoring stations.

Benefits/Advantages

• Broadband performance
• Low-power control
• Compact and modular design
• Scalable and customizable