Physics Practical Magic

Researchers have developed a way to turn an entire room into a wireless charger that powers tiny, battery-free gadgets anywhere in the space.

March 31, 2026

Original Paper

Reconfiguring room-scale magnetoquasistatic wireless power transfer with hierarchical resonators

Takuya Sasatani, Alanson P. Sample, Yoshihiro Kawahara

arXiv · 2603.27305

The Takeaway

Traditional wireless charging is weak and requires devices to be very close to a pad. By using a new 'hierarchical' relay system built into the room's structure, scientists can now concentrate magnetic fields onto specific small devices, increasing charging efficiency by more than 100 times.

From the 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 q