Wirelessly Transfers Electrical Power via Magnetic Resonant Coupling, Maximizing Power Transfer Efficiency, Even in Misaligned Conditions
This highly efficient wireless power transfer (WPT) system uses a rollable metamaterial screen to improve power transfer efficiency (PTE), even in misaligned conditions. There is a high demand for wireless charging in the modern electronics market, leading to active research and development of wireless power transfer (WPT) technologies. Current WPT systems employ the inductive charging approach, limiting power transfer distance and efficiency. Alternatively, magnetic resonance coupling-based WPT enables a greater power transfer range. However, an increase in misalignment levels and transfer distance between the transmitting and receiving coils leads to a decline in PTE. The use of metamaterials to improve transfer efficiency has increased due to their electromagnetic properties, such as evanescent wave amplification and negative refractive characteristics. The placement of metamaterial structures between transmitter and receiver coils increases the efficiency of the WPT systems. Nevertheless, the bulky architectures often lead to substrate loss and do not comply with the technology trend of reduced size, weight, and power.
Researchers at the University of Florida have developed a high-efficiency wireless power transfer (WPT) system based on magnetic resonance coupling, placing a rollable metamaterial screen between transmitter and receiver coils. The screen configures to amplify and focus the magnetic field between transmitter and receiver coils in a non-contact fashion, significantly improving power transfer efficiency (PTE).
Application
Transfers electrical power wirelessly via magnetic resonant coupling, enhanced by the rollable and tunable metamaterial screen, maximizing power transfer efficiency
Advantages
- The metamaterial screen can effectively change the direction of magnetic fields depending on the location of the receiving coil, improving the PTE even at misaligned conditions
- The screen is rollable as needed, not requiring a designated space and enabling users to utilize the space flexibly
- The screen has a thin structure, decreasing substrate loss associated with thicker designs
- The metamaterial screen is tunable, enabling it to focus the magnetic field on the receiver coil’s location and increase power transfer efficiency
Technology
This wireless power transfer (WPT) system utilizes a rollable metamaterial screen to enhance power transfer efficiency (PTE). The system transfers electrical power wirelessly via magnetic resonant coupling operating at 4.5 MHz. The screen is between the transmitting and receiving coils, focusing the magnetic field and significantly improving the PTE. This slab has a fully expanded area of 750 mm x 750 mm and a thin structure with low power losses and excellent rollability. As a result, it is highly compact and portable and does not require any designated space when not in use. Additionally, the metamaterial screen consists of multiple unit cells with tunability properties, enabling them to change the direction of the magnetic field depending on the location of the receiving coil. This feature provides compensation for misalignment between coils, preserving PTE. Each unit cell comprises a square spiral resonator fabricated on a flexible polyethylene substrate, conferring lower power losses than traditional split-ring resonators.
Brochure
