Ultrasonic Lamb Waves for Wireless Power Transfer

Area of Science:

• Materials Science
• Mechanical Engineering
• Electrical Engineering

Background:

• Wireless power transfer (WPT) is often hindered by electromagnetic shielding in metal structures.
• Ultrasonic guided plate waves, specifically Lamb waves, offer a potential solution for WPT through metal plates.
• Piezoelectric transducers are key components for generating and receiving these acoustic waves.

Purpose of the Study:

• To conduct a fundamental study on the performance of Lamb wave-based wireless power transfer.
• To model, simulate, and experimentally verify the efficiency and characteristics of Lamb wave WPT.
• To investigate practical implementation factors for bonding transducers and grounding the plate.

Main Methods:

• Utilized Macro-Fiber Composite (MFC), d33-mode, piezoelectric transducers bonded to an aluminum plate.
• Performed modeling and simulations to predict power transfer efficiency.
• Conducted experimental verification, including load impedance matching and transducer sizing analysis.

Main Results:

• Achieved a power transfer of 0.47 W with 56% overall efficiency at a 204-mm distance.
• Simulated and measured frequency responses for power transfer efficiency showed good agreement.
• Identified that maximum efficiency locations correlate with the zero-order symmetrical (S0) Lamb wave mode patterns.

Conclusions:

• Lamb wave-based WPT is a viable method for efficient, long-distance power transfer through metal plates.
• Transducer bonding methods and electrical grounding significantly impact practical WPT system performance.
• The study provides a foundation for optimizing Lamb wave WPT systems for various applications.