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Wireless Power Transmission

5 Nov, 2012 By: Dr. Satwant Kaur imageSource

As always, imageSource looks to Dr. Satwant Kaur (First Lady of Emerging Technologies) to share cutting edge technology advances, concepts, uses and opportunities with our readers. This month she addresses the emerging technology called Wireless Power Transmission.

[imageSource]: Why do we need WIRELESS POWER TRANSFER (WPT)?

[Satwant]: There are so many places where a power source is needed for many appliances to work, but batteries cannot be there. Examples of such situations include remote underwater locations for temperature and tide sensors, concrete reinforcements for corrosion detectors, or even inside our own body for diagnostic endoscopes, etc. In such instances, ability to deliver power wirelessly where it is needed becomes an enabler to a much larger impact from countless electrical devices.

Wireless Power Transmission (WPT) is the transmission of electrical energy from a power source to an electrical load without a conductive physical connection or interconnecting wires.

Transmission of Power is wirelessly is very different from data communication wirelessly.

Radio waves are used to send and receive cell phone, TV, radio and WiFi data. The radio waves spread in all directions until they reach the antenna that is tuned to the right frequency. Spreading power in a similar way would be not only inefficient but dangerous as well.

Therefore, Wireless Power Transmission (WPT) is done utilizing technologies like inductive coupling.

WPT is increasingly being used to making makes everyday products like cell phones, laptop computers, mobile robots, and electric vehicles capable of re-charging themselves without ever being plugged in. WPT enables Flat screen TV’s to hang on a wall without any wires to power source. Medical devices and implants no longer need wires or
batteries. Pacemakers don’t have to be surgically replenished with batteries every few years.

WT technologies continue to evolve so it can be safely and efficiently over larger and larger distances and deliver power large amount of power.

[imageSource]: What can we do with WPT?

[Satwant]: Wireless Energy Transmission applications enabled by WPT technologies will enable a new tether-less truly mobile
connected world:

Eliminate cords on everything from lamps and laptops and kitchen appliances.

Eliminate need for surgery to replace batteries for pacemakers inside human bodies.

Eliminate chargers for mobile cell phone and cameras chargers.

Eliminate extra installations needed for new power outlets when installing electrical devices.

Eliminate restrictions of distance & need to place electrical product within a limited chord range to the wall outlet.

Eliminate dangers of tripping posed by dangling power cord.

Electrically powered devices will no longer need recharging.

Highways would continuously recharge electric cars that drive on them.

[imageSource]: How does WPT work?

[Satwant]: Wireless power transfer (WPT) is an emerging technology that can wirelessly provide perpetual energy supply to wireless networks and wireless devices. WPT is achieved by either the “near-field” electromagnetic (EM) induction technology or the “far-field” EM radiation (such as radio) for short and long range applications, respectively. Electromagnetic Induction is a near-field method since distances between transmitter and receiver is smaller since magnetic coupling happens in close proximity. Electromagnetic Radiation is a Far-field WPT methods with longer ranges using radio wave and optical devices.

WPT enables Powering of wireless lamps and any other electrical wireless devices that are coupled to them through AC electric current.

It now enables an environment with a powerful, rapidly alternating electrostatic field. Inside this environment, the electrical device can be moved and put anywhere, and that it is powered, no matter where it is put inside that environment and without being electrically connected to anything.

[imageSource]: How does WPT enable Medical Devices to navigate in human organs?

[Satwant]: A capsular endoscope is a medical device used for inspection of the large intestine. The endoscope requires a powered motor for backward movement against the automatic direction of movement in the intestine.

Thus using WPT, the electromagnetic inductance delivers power wirelessly to the remote medical device inside the body.

[imageSource]: WPT enables automatic charging for Electric Vehicles

[Satwant]: WPT enables the process of automatically charging EV.

WPT for Electric Vehicles (EV) wireless charging systems are achieved by having a transmitting induction coil at the charging station and a receiving induction coil in the vehicle. Resonance between the two coils enables efficient charging even when EV is at a distance from charging station. To make the two coils resonant, the transmit frequency should be able to adapt to that of the receiver.

Frequency agile resonance-based wireless charging systems are being developed. They sense the current in the transmitting coil and adapt the frequency such that resonance and maximum efficiency is maintained during wireless power transmission.

[imageSource]: How does WPT enable capsule robots locomotion inside a body?

[Satwant]: The applications of wireless capsule endoscopes are limited without a wireless power supply. WPT solves that problem by creation of a capsule robot that has power supply delivered wirelessly.

Traditional capsule endoscopes have the disadvantages of passive locomotion, which offers very little control of navigation inside body. The limitation was due to the fact that adding electric motors needs more energy and rising of temperature inside body which is dangerous.

Now WPT enables new kinds of active capsule endoscope such as “internal force-static friction capsule robot (capsubot).” These wirelessly powered capsubots not only can be controlled better by professionals but is also safer for patients since they do not carry any batteries.

[imageSource]: How can we use WPT for RFID Sensors that track & monitor remotely?

[Satwant]: RFID (Radio Frequency Identification) passive sensors are traditionally used to track and monitor many items such as in manufacturing and retail.

The new trend is that food companies are also now tracking their delivery trucks using RFID tags on perishable items as well. In such scenarios, trucks need power transmitter that can both recharge and query RFID-based sensors periodically. Also, when the sensors detect a change in their environments, say a temperature change or a theft the tags should have the ability to relay that data back to the transmitter.

This requires active RFID tags that need power. That means that either the RF energy would need to be captured and stored or transmitted continuously. WPT solves this problem by Wireless powering of sensors through the strongly coupled magnetic resonance WPT technology.


Electrical and Electronic devices can now be placed into areas earlier unheard of such as within the human body, since WPT technologies can now bring power wirelessly to these devices anywhere they are placed. In many areas batteries losing charge can be life threatening. Now that fear of losing a charge is put to rest by the environment itself, providing the ability to recharge using WPT anywhere, anytime. The emerging technologies enabled by Wireless Power Transmission are impacting our lives in major ways, and a breathtaking future is ours to behold!

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