New Generation of wireless chargers developed at ITMO

New Generation of Wireless Chargers Developed at ITMO

Here is how they work and why it may change the way we go about our lives

New Generation of Wireless Chargers Developed at ITMO

Here is how they work and why it may change the way we go about our lives

Back in 2017, Apple surprised the world by showcasing a new way to charge the iPhone – not with a wire, but by placing it on top of a special pancake-shaped pad. Samsung soon introduced a similar feature. By now, almost every top-of-the-line smartphone supports wireless charging. But is this technology worth it? And will it be possible someday to have a room full of devices with no wires whatsoever?

Yes, it will! That is exactly what scientists at ITMO are working on right now. Recently, they developed a new kind of wireless charger – a box that evenly distributes a magnetic field within itself. This box can be used to charge multiple devices simultaneously simply by placing the gadgets anywhere inside the box. Read on to find out how a charger like that works, why it is completely safe, and whether it can be expanded to cover an entire room.

Wireless chargers explained: how they work and what is their problem

What's in the box?

Scaling up the box

What ITMO scientists propose

The results so far

Back in 2017, Apple surprised the world by showcasing a new way to charge the iPhone – not with a wire, but by placing it on top of a special pancake-shaped pad. Samsung soon introduced a similar feature. By now, almost every top-of-the-line smartphone supports wireless charging. But is this technology worth it? And will it be possible someday to have a room full of devices with no wires whatsoever?

Yes, it will! That is exactly what scientists at ITMO are working on right now. Recently, they developed a new kind of wireless charger – a box that evenly distributes a magnetic field within itself. This box can be used to charge multiple devices simultaneously simply by placing the gadgets anywhere inside the box. Read on to find out how a charger like that works, why it is completely safe, and whether it can be expanded to cover an entire room.

Wireless chargers explained: how they work and what is their problem

What's in the box?

Scaling up the box

What ITMO scientists propose

The results so far

Wireless Chargers Explained: How They Work and What Is Their Problem

To start with, let us understand their design. Inside the wireless chargers that are now used on iPhones or other modern smartphones is a special piece of wire wound into the shape of a coil. A similar coil is also built into the smartphones that support this technology.

This method of wireless power transfer is based on the law of electromagnetic induction discovered by Michael Faraday back in 1831. When an alternating current passes through a coil, electrons come into motion and surround it with an electromagnetic field. This field can, in turn, “activate” the electrons in the coils of smartphones, which charge the device.

But there is a catch: this method can only transfer energy up to 4 centimeters away, so the phone has to be practically touching the charger. Moreover, a charger from one manufacturer is not compatible with another company’s device.

What ITMO Scientists Propose

Pavel Seregin, a junior researcher
at the Faculty of Physics:

Scientists from ITMO’s Faculty of Physics came up with a way to wirelessly and safely transfer energy across longer distances. Instead of simple inductive power transfer, they used resonant power transfer as a basis for their technology.

”Resonant wireless power transfer differs from inductive in that the system includes additional capacitors which allow the magnetic field to extend further. In other words, using resonance, we can cover the entire volume of the box evenly.”

Incidentally, wireless power transfer over large distances using electric resonance was devised by Nikola Tesla all the way back at the beginning of the 20th century. Engineers spent the next hundred years trying and failing to transform this invention into a usable and effective system. Now though, thanks to technological advances, it is possible.

In recent years, researchers from the University of Tokyo and the University of Michigan have been working on charging multiple devices within a volume of space (their article was published in the acclaimed Nature Electronics journal in 2021). Their main idea was to use a structure of conductive surfaces (sheets of metal) and capacitors to form an oscillating circuit (resonator). This would result in a room filled with a magnetic field that can electromagnetically interact with small receiver coils attached to gadgets.

In the early stages of their research, ITMO scientists first built a replica of the design from the journal within their lab. However, they quickly realized a flaw in the technology – the magnetic field inside such a structure is not uniform. It is effectively concentrated in the center of the room. So in order to quickly charge a device (for example, a smartphone) in this room, the user will have to hold it in its center while constantly turning it in their hands so that the magnetic flux passes the smartphone’s coil in the most efficient manner. Besides, large sheets of metal make this tech rather difficult to integrate into an environment.

In the end, the team from ITMO suggested their own design. A prototype has already been built, a box that is 50 cubic centimeters in size, which can be used to charge at least three devices simultaneously. And where the gadgets are within the box does not matter. Power will always be supplied at peak efficiency. The box functions at the frequency of 100 kHz, which falls within the Qi standard supported by most smartphone manufacturers.

Pavel Seregin,
a junior researcher
at the Faculty of Physics:

Scientists from ITMO’s Faculty of Physics came up with a way to wirelessly and safely transfer energy across longer distances. Instead of simple inductive power transfer, they used resonant power transfer as a basis for their technology.

”Resonant wireless power transfer differs from inductive in that the system includes additional capacitors which allow the magnetic field to extend further. In other words, using resonance, we can cover the entire volume of the box evenly.”

Incidentally, wireless power transfer over large distances using electric resonance was devised by Nikola Tesla all the way back at the beginning of the 20th century. Engineers spent the next hundred years trying and failing to transform this invention into a usable and effective system. Now though, thanks to technological advances, it is possible.

In recent years, researchers from the University of Tokyo and the University of Michigan have been working on charging multiple devices within a volume of space (their article was published in the acclaimed Nature Electronics journal in 2021). Their main idea was to use a structure of conductive surfaces (sheets of metal) and capacitors to form an oscillating circuit (resonator). This would result in a room filled with a magnetic field that can electromagnetically interact with small receiver coils attached to gadgets.

In the early stages of their research, ITMO scientists first built a replica of the design from the journal within their lab. However, they quickly realized a flaw in the technology – the magnetic field inside such a structure is not uniform. It is effectively concentrated in the center of the room. So in order to quickly charge a device (for example, a smartphone) in this room, the user will have to hold it in its center while constantly turning it in their hands so that the magnetic flux passes the smartphone’s coil in the most efficient manner. Besides, large sheets of metal make this tech rather difficult to integrate into an environment.

In the end, the team from ITMO suggested their own design. A prototype has already been built, a box that is 50 cubic centimeters in size, which can be used to charge at least three devices simultaneously. And where the gadgets are within the box does not matter. Power will always be supplied at peak efficiency. The box functions at the frequency of 100 kHz, which falls within the Qi standard supported by most smartphone manufacturers.

The Results So Far

Uniformity

Safety

Efficiency

The design by ITMO scientists distributes the oscillating magnetic field within its working area uniformly (over 80% is covered) – which is why devices can be charged anywhere within the box with the same efficiency.

Said energy transfer efficiency is over 50% ― power input of just five watts is enough to charge multiple devices

Based on an analysis of the intensities of the magnetic and electric fields, scientists have established that they comply with the notable international safety standards. Furthermore, the design does not interfere with the functions of electrical appliances on the outside of the box because the entirety of the electromagnetic field is contained within.

>80%

>50%

100%

Uniformity

Safety

Efficiency

The design by ITMO scientists distributes the oscillating magnetic field within its working area uniformly (over 80% is covered) – which is why devices can be charged anywhere within the box with the same efficiency.

Said energy transfer efficiency is over 50% ― power input of just five watts is enough to charge multiple devices.

Based on an analysis of the intensities of the magnetic and electric fields, scientists have established that they comply with the notable international safety standards. Furthermore, the design does not interfere with the functions of electrical appliances on the outside of the box because the entirety of the electromagnetic field is contained within.

>80%

>50%

100%

“The idea to construct a resonator that will create a uniform field came from a different area of study. A part of our faculty’s team spent many years developing resonant devices – wireless radiofrequency coils based on metamaterials and metasurfaces for MRI.

Alena Schelokova,
a researcher at the Faculty of Physics:

We achieved remarkable results, so at some point, Pavel Belov, our chief research associate, suggested we apply this experience to our wireless power transfer project. In MRI design, we use resonators that function at the same frequency as the whole-body coil built into the MR scanner. The coupling between the two resonators allows us to focus the magnetic field in the area that is being studied and diagnosed. This project uses a similar principle.”

For instance, ITMO scientists already developed a compact portable wireless device to screen breasts for cancerous tumors.

The researchers are also working on a portable scanner for head MRI.

“The idea to construct a resonator that will create a uniform field came from a different area of study. A part of our faculty’s team spent many years developing resonant devices – wireless radiofrequency coils based on metamaterials and metasurfaces for MRI.

Alena Schelokova,
a researcher at the Faculty of Physics:

We achieved remarkable results, so at some point, Pavel Belov, our chief research associate, suggested we apply this experience to our wireless power transfer project. In MRI design, we use resonators that function at the same frequency as the whole-body coil built into the MR scanner. The coupling between the two resonators allows us to focus the magnetic field in the area that is being studied and diagnosed. This project uses a similar principle.”

For instance, ITMO scientists already developed a compact portable wireless device to screen breasts for cancerous tumors.

The researchers are also working on a portable scanner for head MRI.

What’s in the Box?

Resonator

Receivers

Power supply point

A resonator consisting of conductors. The conductors are linked by high-quality capacitors responsible for adjusting the system’s oscillation frequency. The resonator lies at the heart of the design, as it is used to create the magnetic field. The field then induces the current in the gadget’s coils; if the current is powerful enough, the device inside the box recharges

Coils, which are small wires wound in a particular way, and capacitors act as receivers for the transferred energy. These coils are integrated into various electronic devices: decorative figurines, toys, or smartphone cases

The box is powered via a cable that is connected to its port. That means the resonator is fed from outside through a socket and then transfers that energy to the devices within

What’s in the Box?

Resonator

Receivers

Power supply point

A resonator consisting of conductors. The conductors are linked by high-quality capacitors responsible for adjusting the system’s oscillation frequency. The resonator lies at the heart of the design, as it is used to create the magnetic field. The field then induces the current in the gadget’s coils; if the current is powerful enough, the device inside the box recharges

Coils, which are small wires wound in a particular way, and capacitors act as receivers for the transferred energy. These coils are integrated into various electronic devices: decorative figurines, toys, or smartphone cases

The box is powered via a cable that is connected to its port. That means the resonator is fed from outside through a socket and then transfers that energy to the devices within

Scaling Up the Box

Imagine coming home and charging your phone not by putting it on the table but inside the table, along with the rest of your gadgets. According to the developers, the design and versatility of the box allow it to be integrated into various environments – for instance, it can be embedded within a shelf or another piece of furniture.

Alternatively, the box can be a B2B product. For example, it can be scaled up to serve as a charging station for a whole group of drones or as part of operating a warehouse with several devices in need of a simultaneous recharge.

Already the team has started on their next task – scaling up their small box to be the size of a room (e.g., three by three cubic meters) that can also charge several devices simultaneously.

At this first stage, researchers have to determine the future operating frequencies of the wireless room. Low frequencies in such a large space will make it challenging to achieve the necessary magnetic field uniformity and charging efficiency. For instance, the aforementioned QI standard (the lowest of all frequencies) is unsuitable for big rooms.

There are quite a few. For example, A4WP, PMA, and Qi. Note that the Qi is among the most popular. It can be used in one of two ways: either on a low frequency – zero to five watts, or medium – up to 30-65 watts. Qi has been adopted by various manufacturers, such as Apple, Asus, Huawei, Samsung, Xiaomi, Sony, etc.

What are the existing standards of wireless power transfer?

This research project was conducted with support from the Priority 2030 program. The research team now works in several directions, with some running calculations, others administering experimental studies and hardware development, and some promoting their product while looking for new business partners. Notably, 60% of the team comprises ITMO students. However, the team plans on expanding in the future. For instance, they are looking for design specialists at this moment.

At this first stage, researchers have to determine the future operating frequencies of the wireless room. Low frequencies in such a large space will make it challenging to achieve the necessary magnetic field uniformity and charging efficiency. For instance, the aforementioned QI standard (the lowest of all frequencies) is unsuitable for big rooms.

There are quite a few. For example, A4WP, PMA, and Qi. Note that the Qi is among the most popular. It can be used in one of two ways: either on a low frequency – zero to five watts, or medium – up to 30-65 watts. Qi has been adopted by various manufacturers, such as Apple, Asus, Huawei, Samsung, Xiaomi, Sony, etc.

What are the existing standards of wireless power transfer?

This research project was conducted with support from the Priority 2030 program. The research team now works in several directions, with some running calculations, others administering experimental studies and hardware development, and some promoting their product while looking for new business partners. Notably, 60% of the team comprises ITMO students. However, the team plans on expanding in the future. For instance, they are looking for design specialists at this moment.

Research team:

Alena Schelokova, Pavel Belov, Polina Petrova, Pavel Seregin, Nikita Mikhailov, Aigerim Jandaliyeva, Mikhail Udrov, Mikhail Siganov, Aleksandra Skobeleva, ‪Georgiy Kurganov‬, Leila Suleiman, Andrey Vdovenko, Sergey Vlasov, Polina Kapitanova, Irina Melchakova

Creators:

Text by: Elena Menshikova
Photo and video content by: Dmitry Grigoryev / ITMO.NEWS, the Faculty of Physics
Layout by: Ekaterina Shevyreva
Translation by: Mikhail Evdokimov