Electrode Coverage Optimization for Piezoelectric Energy Harvesting from Tip Excitation

Area of Science:

• Energy Harvesting
• Materials Science
• Electrical Engineering

Background:

• Cantilever-type piezoelectric energy harvesting is crucial for wireless sensor networks but limited by low power output.
• Improving power conversion efficiency is key for commercializing piezoelectric energy harvesting devices.

Purpose of the Study:

• To investigate the impact of electrode coverage ratio on the performance of piezoelectric beams for enhanced energy harvesting.
• To optimize electrode coverage for maximum power output in piezoelectric energy harvesters.

Main Methods:

• A distributed-parameter theoretical model was developed for a bimorph piezoelectric beam, incorporating electrode coverage.
• Experimental validation was performed using a fabricated piezoelectric beam with segmented electrodes.

Main Results:

• Theoretical analysis and experiments show optimal performance at 66.1% electrode coverage.
• A 12% improvement in Root-Mean-Square (RMS) output power was achieved with the optimized electrode coverage.
• Electrode coverage significantly influences capacitance and optimal load resistance.

Conclusions:

• Optimizing electrode coverage is a simple yet effective method to enhance piezoelectric energy harvesting efficiency.
• The findings provide a practical approach to improve power supplies for wireless sensor networks using piezoelectric beams.