Project Description

Magnetic Coupled Resonance

Traditional inductive chargers require docking stations for precise alignment and near contact distance to achieve efficient power transfer. In contrast magnetic coupled resonance is a near-field phenomenon in which high-Q transmit and receive coils are loosely coupled allowing for greater wireless transfer range while maintaining high efficiency. We developed a mathematical model that provides new insight in to critical system parameters such as frequency splitting, critical coupling, and impedance matching. We have demonstrated the ability to safely transfer large amounts of power (+60Watts), over a distance of several feet, at greater then 90% efficiency.

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The Over Coupled Regime

Coupled resonator systems with sufficiently high-Q coils exhibit a surprising behavior: power transfer efficiency can be maximal and nearly independent of distance and orientation. In this regime, which typically extends several feet for our frequency and coil designs, the system is said to be over-coupled. We call this regime the "magic regime," though, since it is what fundamentally differentiates this technology. The extent of the magic regime, which is bounded by a critical coupling point, is a key figure of merit which can be used to compare performance of disparate implementations.

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Safety

Coupled resonator systems with sufficiently high-Q coils exhibit a surprising behavior: power transfer efficiency can be maximal and nearly independent of distance and orientation. In this regime, which typically extends several feet for our frequency and coil designs, the system is said to be over-coupled. We call this regime the "magic regime," though, since it is what fundamentally differentiates this technology. The extent of the magic regime, which is bounded by a critical coupling point, is a key figure of merit which can be used to compare performance of disparate implementations.

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Applications

Coupled resonator systems with sufficiently high-Q coils exhibit a surprising behavior: power transfer efficiency can be maximal and nearly independent of distance and orientation. In this regime, which typically extends several feet for our frequency and coil designs, the system is said to be over-coupled. We call this regime the "magic regime," though, since it is what fundamentally differentiates this technology. The extent of the magic regime, which is bounded by a critical coupling point, is a key figure of merit which can be used to compare performance of disparate implementations.

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Videos

Initial demonstration of wireless power transfer using magnetic coupled resonance showing 60 watts of power, transferred over a distance of two feet, at 90% efficiency.

Demonstration of auto tuning techniques that enable near constant power transfer efficiency while operating in the over-coupled regime.

Emily Cooper presents WREL and a wirelessly powered speaker at Research at Intel Day in 2009.

Additional Videos:

Tech Transfer

In both academia and industry it is always great to see your research make it off the page, out of the lab, and into the real world. Often times this means handing off your favorite projects to other talented people who will carry them to the goal line. Here I am defining a Tech Transfer as an effort to commercialize one of my research projects that has become public.

Intel

While working at Intel Research, Seattle our team explored a number wireless charging concepts, developed Intellectual Property, and general wireless power expertise. In 2010 we transferred the project to an internal product team who publically announced a proof of concept at the 2012 Intel Developer Forum. As covered by Legit Review Intel demonstrated a proximity charging solution based on resonant wireless power transfer where an UltraBook (laptop) would charge a near by smart phone. This was followed by an announcement that Intel would be partnering with the chip manufacture IDT to develop a integrated transmitter and receiver chipset based on our resonant wireless power transfer technology.

IDF 2012: Intel Wireless Charging Technology (WCT) - Legit Review 2012

IDT and Intel Partner to Develop Integrated Silicon Solution for Intel’s Wireless Charging Technology - Press Release, 2012


Wibotic

Wibotic was founded in 2015 by Ben Waters and Joshua Smith as a spin out of the Sensor Systems lab at the University of Washington. The company focuses on providing wireless charging solutions for autonomous robots such as drones, mobile robots, and underwater vehicles. As Ben and Josh have taken the technology to the next step with Wibotic, its great to see some of the initial work we did in the lab make it out into the real world.

Related Publication

Related Projects

Thumb-NCF-WISP

Free-range Resonant Electrical Energy Delivery (FREE-D)

The FREE-D system uses magnetic coupled resonance to efficiently transfer power wirelessly to implanted heart pumps known as LVADs. The use of wireless power eliminates the need for the transcutaneous driveline, which is the leading cause of LVAD complications and patient re-hospitalization.

6 Papers
1 Video

Collaborators

This project orginated at Intel Research, Seattle (which has since closed) and the research has contiuned in Sensor Systems Lab led by Joshua Smith at the University of Washington.