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JD: What do you feel consumers are really looking for from wireless power transfer (WPT) technologies?


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HZ: This question really has a couple of parts: what the consumers want and what the consumers will end up using/needing. To answer the “want” question, we have to look at the actual problems with our devices. First, cell phones require that users remember to charge their devices. In that process, users have to use some type of charger near a wall socket. None of today’s available WPT technologies address these two core problems, and users are voting with their wallets. The “need” presents a larger wireless-power challenge for all the other devices and sensors we have in our life: remote controls, digital cameras, wireless keyboards and mice, tablets, game controllers, motion sensors, and smoke detectors—to name a few.

Due to their distribution in our environments and their quantities, we need a radical new solution that can address the power needs of these devices. When we solve this challenge, we will open the door for a truly wireless world that enables all of the intriguing designs of what we call the “Internet of Things.” In short, people will stop thinking of their devices’ batteries and start thinking of unrestricted use of their devices instead.

Hatem Zeine

JD: Which frequency ranges do you think are the most viable for WPT implementations now and in the future?

HZ: The different use cases of WPT will demand different spectrum sections for us—especially when we consider loss of energy in transmission. Medium- (>20-W) to high-power (>1-kW)  applications will inevitably need frequencies that are not absorbed by human flesh, as a mere 5% of power loss could amount to 700 W of power when charging an electric vehicle. This restricts WPT to frequencies below 50 MHz. The caveat of using such frequencies is that the energy cannot be focused at a distance, due to the long wavelength used in lieu of basketball-field-sized chargers. Low (<5-W) power applications, such as cell phones, can leverage the same frequencies (<50 MHz). But they would restrict the charging distance to a charging pad. Remote power delivery will require a wavelength that can be focused with small transmitters.

In addition, the power will have to be focused to a small (device-sized) region. Such wavelengths need to be a minimum of 1 in. to a maximum of 12 in., resulting in frequencies ranging from ~1 to ~12 GHz (give or take a few). Our remote wireless power uses the 2.4-GHz ISM band to deliver safe power at a distance of 30 ft.

JD: Why haven’t WPT chargers for mobile devices been more successful?

HZ: Currently, people do not view a WPT charger as a utility. Most people find that the WPT chargers available today do not change their habits or device usage. The added value is not obvious when having a phone with a WPT charging pad, as we still end up needing to remember to charge the device. And when it is charging, it is away from us. The device is not any better in terms of size/weight/design, so the user barely perceives the gain. Remember that all of the market-available WPT chargers power devices at a distance of no more than an inch from a pad that is connected to a wall power socket.

We believe that remote wireless charging will change our habits when users never have to charge their devices because they are receiving power all the time. The devices will then need smaller batteries, hence better designs and use.

JD: Do you feel that the main focus for WPT charging systems has been designed for a charging-pad approach?

HZ: The prevailing technology of wireless charging (which should be called “contactless charging”) has been inductive coupling, as seen by electric toothbrushes from the late 1960s and early 1970s. The more recent innovations in magnetic resonance have extended the range of coil-based WPT. But it has not liberated the device from the charger. What we are seeing today is the resurgence of coil-based technology in the marketplace, offering short-range power to devices without attaching contacts. It was simply the only option available.

JD: What major hurdles are faced by companies looking to implement a WPT system?

HZ: I think the biggest obstacle is having enough engineering “manpower” to help make their concept a reality and get to market. Because WPT is an emerging technology, new and innovative engineering techniques are required. Additionally, a real wireless-power solution, such as the one that Ossia has developed with Cota, requires many complex design elements to achieve all of the functionality desired by users. Examples include a 30-ft. charging distance, non-line-of-sight, efficiency, and being able to scale the technology to the next level. Finding engineers with the right RF experience is often challenging, so we are always looking for engineers with this type of background.  

JD: Is the major focus of WPT technologies on the commercial, industrial, or military sectors?

HZ: WPT serves all electronic devices, no matter what their application is. The most famous are smartphone chargers because there are so many smartphones and so much hassle with charging them. However, there are applications of wireless/contactless power transmission for industrial robotics, such as warehouse handheld scanners, that have just started being addressed. The tech companies supplying WPT will go where the money is. Where the smartphone market is concerned, it is really the 800-lb. gorilla in the room due to its fast churn and the vast financial resources that are available. We believe that our technologies will have a major impact on consumer devices as well as industrial sensors/controls, as both of these markets are reaching bottlenecks in technology advancement due to power availability.

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EMI And Safety Concerns

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JD: Does the congestion of electromagnetic interference (EMI) hamper WPT technologies?  

HZ: As discussed earlier, different WPT technologies utilize different spectrum segments. All have to follow the guidance set by the FCC in the United States and international legislative bodies elsewhere. Thankfully, wireless power is almost by definition un-encoded. When properly designed, it can have little/manageable impact on encoded communication in the same spectrum.

JD: What are the safety concerns for WPT technologies, and how are they being addressed?

HZ: Safety concerns are paramount in the design of power systems—and even more so for wireless power systems, as the energy is not confined to the wires or components. The ability for the human body to absorb the energy presented by the WPT is a feature that impacts the maximum power levels. For instance, lower frequencies are absorbed less by human flesh. But the energy levels used are much higher (a car charger would require 7-kW power transfer, for example) and a small percentage loss would be large and potentially harmful.

JD: What technological leap forward would be the most advantageous for WPT technologies?

HZ: We believe that delivering safe, focused, and remote power is a huge leap of utility for users in consumer or industrial markets. Once WPT enters the market, it will ignite the imagination of product designers everywhere. We will see devices that serve us throughout our environment ranging from intelligent door handles to self-heating cups, displays on “inanimate” objects, and feedback from every device. The Internet genie will no longer be trapped in laptops and smartphones.

JD: Do you believe the WPT market will have room for both short-range (such as Rezence) and long-range (i.e., COTA) solutions?

HZ: Most of the wireless power standards, such as Rezence, are for charging mobile devices like cell phones, Bluetooth headsets, and the like. Their targets range from devices that require user attention to devices that are running out of power (something that is easy to know for a cell phone). But our homes are full of devices that have no visible or easily accessible battery indicators, such as security motion sensors, remote controls, clocks, flashlights, car key fobs, kids’ toys, etc. With such devices, people have generally let the batteries die first and then charged/replaced them.

The short-range technologies underneath the wireless-charging consortiums have great value in some vertical markets, where proximity power delivery is of benefit. Examples include electric-vehicle charging and robotics. All of these consortiums continue to demonstrate the importance and need to rapidly adopt a wireless power solution.  Yet I believe that this need goes far beyond simply charging a smartphone. It includes charging all types of devices throughout a home, which requires a longer-distance charging solution. In the end, we believe Cota-based systems will power the small devices while Rezence or similar technologies will power the larger, more power-hungry devices like blenders, toasters, and cars.

JD: Why did you pursue WPT technologies as an entrepreneurial path?

HZ: In 2002, while experimenting with phased-array transmissions, I discovered something extremely remarkable. In addition to transmitting data, the array could also transmit power. After years of experimentation and research, we filed our first patent in 2007. Shortly afterward, I began to assemble a team of RF engineers and the foundation for what we call “Cota” was designed. Since then, we have refined our designs and patented our inventions.


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Whereas many inventions are derived out of necessity or market need, sometimes the best inventions are discovered by accident. We were not looking to solve a specific market need at the time. I feel that this ultimately freed our minds to the endless possibilities of the Cota technology, which go far beyond simply charging a phone. If you start from the market need, you are pushed to use and improve what is available on hand. This probably explains why WPT is still using 40+-year-old technology. Although breakthrough discoveries cannot be created within a certain time frame, they need to be pursued despite challenges.

JD: What has been your greatest success so far?

HZ: My greatest success so far has been our ability to demonstrate a real wireless power solution via our working prototype on the stage at TechCrunch Disrupt in fall 2013. We look forward to delivering our first commercially ready technology in the near future.

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