How Aalto University’s Grid‑Based Wireless Power Transfer Could Power the Future

In the era of big data, power delivery must become truly wireless to enhance next‑generation mobile devices.

A novel wireless power transfer technology, currently under public testing, can charge devices anywhere within a designated area without cables or plugs.

The system works for warehouse robots, kitchen appliances, phones, laptops, and will soon power moving electric vehicles.

Traditional wireless power systems either use a single large transmitter, causing unnecessary electromagnetic radiation, or many small transmitters that require precise alignment and position tracking.

Researchers at Aalto University have solved these issues by arranging transmitters in a grid where adjacent transmitters carry currents in opposite directions, forming a chess‑board pattern of “positive” and “negative” coils that generate magnetic flux.

Receivers above the grid capture the flux between opposite coils, inducing current to charge the device.

The principle was detailed in the paper “Self‑tuning Omnidirectional Wireless Power Transfer using Double Toroidal Helix Coils” published in IEEE Transactions on Industrial Electronics.

Post‑doctoral researcher Prasad Jayathurathnage explains that the system requires no high‑end processors or extensive computation; it simply detects the presence of a receiver and activates power transfer.

When a receiver is present, power is transmitted only to that device, allowing multiple devices to charge simultaneously without energizing the entire area.

Transmitters can be tiled to create a charging zone of any size; a subset of transmitters is activated at low power, listening for receivers, and switches to a warning mode to deliver power as soon as a receiver appears.

Co‑researcher Shamsul Al Mahmud notes that the configuration provides nearly constant power regardless of the receiver’s position or orientation, even while the device moves.

The technology is being tested with Finnish company Solteq Robotics on commercial warehouse inventory robots, and a new project, Parkzia, aims to commercialize the system for industrial and transportation use.

Future goals include scaling charging power from about 1 kW to over 20 kW to enable electric‑vehicle charging.