Witricity is nothing but wireless electricity. Transmission of electrical energy from oneobject to another without the use of wires iscalled as Witricity. Because of Witricity some of the devices wontrequire batteries to operate.2
4.The story started late one nighta few years ago. It was probablythe sixth time that month thatMIT Professor Marin Soljacicwas awakened by his mobilephone beeping battery low. Atthat time it occurred to him thatthere is electricity wired allthrough his house, office-everywhere. He think about- howit is possible to use electricitywithout using wires…Eureka! Coupled Resonators
Electricity is a general term thatencompasses a variety ofphenomena resulting from thepresence and flow of electriccharge.Magnetism is a force that acts at adistance due to a magnetic field.This field is caused by movingelectrically charged particles or isinherent in magnetic objects suchas magnet.6
Electromagnetic induction is theproduction of voltage across aconductor moving through amagnetic field.Electromagnetism is one of thefour fundamental interactions ofnature, along with stronginteraction, weak interaction andgravitation. It is the force thatcauses the interaction betweenelectrically charged particles; theareas in which this happens arecalled electromagnetic fieldsEnergy/Power Coupling: Energycoupling occurs when an energysource has a means oftransferring energy to anotherobject 7
Resonance :is the tendency of asystem to oscillate with largeramplitude at some frequenciesthan at others. These are knownas the systems resonantfrequencies (or resonancefrequencies). At thesefrequencies, even small periodicdriving forces can produce largeamplitude oscillationsResonant Magnetic Coupling:Magnetic coupling occurs whentwo objects exchange energythrough their varying oroscillating magnetic fields.Resonant coupling occurs whenthe natural frequencies of the twoobjects are approximately thesame. 8
9The Transfer of Electricity from one place to another withoutwires is known as “Witricity”.There is witricity power sources(transmitter) and capturedevices(receiver).Power source provides power to the devices where as capturedevice captured it to work.Power source and capture devices are specially designedmagnetic resonators.Magnetic resonators efficiently transfer power over largedistance via the magnetic near-field.
102007: A physicsresearch group, led byProf. Marin Soljacic,at MIT,wirelessly power a 60Wlight bulb with 40%efficiency at a 2 meters(6.6 ft) distance using two60 cm-diameter coilsThe first experiment of witricity, the concept ofwireless electricity, was conducted in the year 2006, byresearchers from Massachusetts Institute ofTechnology. The Assistant Professor of this team ofresearchers was Marin Soljacic.
Non radiative energy transfer Safe for living beings and otherenvironmental objectsFlexible geometry Device that can fit into OEM(original equipmentmanufactures)products14Scalable design From Mw to kWEnergy transfer via magnetic nearfieldCan penetrate and wrap aroundobstaclesHighly resonant strong coupling High efficiency over distanceWitricity’s Technology Technology Benefit
Direct wireless power-within the range ofwitricity power sourceAutomatic wireless charging- both in and outof range of its witricity power source.15
Wastage of power issmall .Negative healthimplications.Highly efficient thanelectromagneticinductionLess costly. No need of line of sight. No need of power cablesand batteries. Does not interfere withradio waves.17
Wireless power transmission can bepossible only in few meters. Efficiency is only about 40%.18
Teams’ next aim is to get a robotic vacuumor a laptop working, charging devicesplaced any where in the room and evenrobots on factory floors. In another 3 to 5 years time. they will comeup with a witricity for commercial use. It can also be used in cars to connect eachelectronic equipment with a single trammisted coil19