Reconfiguring room-scale magnetoquasistatic wireless power transfer with hierarchical resonators

2026-03-28

AI Summary

This work addresses the significant efficiency drop in room-scale quasi-static wireless power transfer when powering small receivers (e.g., centimeter-scale or misaligned), caused by diffuse magnetic field distributions and weak coupling. To overcome this, the authors propose a selectively activatable, hierarchical resonant relay architecture that dynamically reconfigures the magnetic field within the cavity to focus energy directionally and deliver high-density power locally to the target receiver. This approach enables, for the first time, on-demand reconfiguration of room-scale magneto-quasi-static fields, achieving up to 500 mW of DC power output on a 15 mm receiver—improving transfer efficiency by over two orders of magnitude compared to conventional methods. The system’s practicality is further demonstrated through multi-relay coordination and integration into furniture for embedded charging applications.

Abstract

Magnetoquasistatic wireless power transfer can deliver substantial power to mobile devices over near-field links. Room-scale implementations, such as quasistatic cavity resonators, extend this capability over large enclosed volumes, but their efficiency drops sharply for centimeter-scale or misoriented receivers because the magnetic field is spatially broad and weakly coupled to small coils. Here, we introduce hierarchical resonators that act as selectively activated relays within a room-scale quasistatic cavity resonator, capturing the ambient magnetic field and re-emitting it to concentrate flux at a target receiver. This architecture reconfigures the wireless power environment on demand and enables localized energy delivery to miniature devices. Experimentally, the hierarchical link improves power transfer efficiency by more than two orders of magnitude relative to direct room-scale transfer and delivers up to 500 mW of DC power to a 15 mm receiver. We further demonstrate selective multi-relay operation and field reorientation for furniture-embedded charging scenarios. These results establish a scalable route to reconfigurable wireless power delivery for miniature and batteryless devices in room-scale environments.

Problem

• magnetoquasistatic
• wireless power transfer
• room-scale
• efficiency
• miniature receivers

Innovation

• hierarchical resonators
• magnetoquasistatic wireless power transfer
• room-scale charging
• flux concentration
• reconfigurable power delivery