Japanese power breakthrough could be ‘step toward a fully wireless society’
Japan scientists have developed a new very effective method for the design of wireless power transfer systems (WPT). Depending on automatic learning, the method allows a system to maintain stable tension even if the loads change – a key step towards a wider adoption of wireless power.
WPT systems are already a key element of many devices, smartphones and biomedical sensors with induction stovetops, which use WPT mechanics to heat kitchen utensils. But one of the main problems of current technology is that it fights against power fluctuations. Indeed, they are dependent on the load, which means that the performance of a system is considerably affected by the supplied device (load).
Devices and smartphones rely on constant and regulated tension to load their batteries safely. The resistance of a battery to electricity changes when it fills, which, in a WPT system dependent on the load, can fluctuate the voltage. This can damage the device or reduce the load speed.
In comparison, the new automatic learning approach is independent of the load (LI), which means that they can provide coherent power and maintain high efficiency, regardless of the device. In the example of the smartphone battery, this means that the power supply will continue to be effectively transferred to a regular voltage, whatever the resistance fluctuations that can occur when the battery fills.
This is particularly important for larger batteries in more complex applications, such as electric vehicles, where the load can move considerably during load.
Researchers revealed their results in a new study published in June 2025 in the journal IEEE transactions on circuits and systems.
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WPT systems work through a process called resonance, in the same way as a radio or a television receives a live signal. A transmitter diffuses a specific frequency of electromagnetic wave by adjusting the way in which the power oscillates between a capacitor and the inductor. When the wave reaches a receiver circuit set to the same frequency, the two resonate, considerably amplifying the signal.
In a radio, the signal is then sent to other components to be amplified and demodulated to create a sound, while in a WPT system, this resonance allows the receiver to capture and store wireless energy.
Automatic learning to stimulate wireless power supply
The new technique uses automatic learning to model and optimize fewer supply transfer systems dependent on the load. The process consists in building a virtual model of the system, then carrying out simulations of the model in action while an artificial intelligence observes it.
AI judges the functioning of the system, as a function of criteria as the amount of power lost as heat and the cleanliness of the electrical signal. He then uses a test and error method to optimize the system so that it works with maximum efficiency, transferring power with a minimum of fluctuations and energy dissipation.
Using their new method, researchers have reduced fluctuations to 5%, compared to 18% using a load dependent system, depending on the study. They have also increased the efficiency of energy transfer to 86.7%, while load dependent systems can operate As low as 65% efficiency.
WPT systems independent of charges have large implications far beyond wireless charge devices, the said main author of the study Hiroo SekiyaProfessor at the Graduate School of Advanced Integration Science at the University of Chiba.
“We are convinced that the results of this research are an important step towards an entirely wireless company,” he said in a statement. “In addition, due to the operation of Li, the WPT system can be built in a simple way, thus reducing the cost and the size. Our goal is to make the WPT banal in the next 5 to 10 years.”
This study also illustrates the ways in which AI can be used to improve the design of electrical circuits, leading to a transformation of “how food electronics are designed, evolving to a future of automated circuits design”, the researchers said in a press release.
