Introduction & Invention
The term WiTricity is derived from the combination
of two words wireless + electricity.
In 1891, Sir Nicola Tesla proposed a method of
wireless power transmission. But it was in most
radiative mode, so most of the power is wasted
But later this concept was attracted by MIT
professor Mr. Marin Soljacic.
The story started late one night the few years
ago. It was probably sixth time of that month.
Mr. Marin was awakened by his mobile phone
beeping low battery warning signal.
At that time he thought about the
transmission of electricity without wires.
This is a most important cause for WiTricity.
The basic principle involved in WiTricity concept
is, Two objects having same resonating frequency
and in Magnetic resonance at Strongly coupled
regime tend to exchange energy , while dissipating
relatively little energy to the extraneous off-
In 1899,Tesla achieved a major breakthrough in his
work at Colorado by transmitting 100 million volts
of electric power wirelessly over a distance of 26
miles to light up a bank of 200 light bulbs and run
one electric motor.
Sir Nicola Tesla
A Tesla Coil produces high voltage electric arcs.
These arcs cause permanent damage to electrical
devices on contact
It is not capable of working in Direct Current, It
works only in Alternating Current.
Types of WiTricity
In general, witricity is classified into three
types, they are:
Short range; Inductive Coupling.
Medium range; Resonant Induction.
Long range; Electromagnetic Wave Power Transfer.
Short Range Medium Range Long Range 10
Inductive coupling works on the principles of electromagnetism.
When a current (electricity) passes through a wire, it generates a
magnetic field perpendicular to the wire.
When a wire is in proximity to a magnetic field, it generates a current
in that wire.
Magnetic fields decay quickly , making inductive coupling effective
only at very short ranges.
Resonant induction still uses the same principles as
magnetic induction (magnetic fields to transfer
current) , but it uses resonance to increase the
range at which the transfer can efficiently take
“Resonance", a phenomenon that causes an object
to vibrate when energy of a certain frequency is
Everything resonates at a certain frequency, based on its
shape and material.
Energy transfers easily between resonating objects. An
example of this is when an opera singer shatters wine
glasses by singing at the frequency at which the glasses
With resonant induction, power is transmitted between
two resonating coils.
Our experimental scheme consists of two Self-resonant
coils. One coil (source coil) is coupled inductively to an
oscillating circuit; the other (device coil) is coupled
inductively to a resistive load. Self-resonant coils rely on
the interplay between distributed inductance and
distributed capacitance to achieve resonance.
Experimental Design Electrical Resonance15
In long range the electricity is converted into
microwaves and transmitted for a long
It is a on going research in the field of WiTricity
Is wiTricity safe?
Many are concerned about another radio fields or frequency
flying through the air. Some believe that these are harmful to
the body but there is little evidence to suggest they are.
WiTricity, however, turns electricity into a magnetic field, which
is a non-radiative transfer method. Magnetism interacts very
minimally with biological organisms and is not harmful at all to
humans or animals.
WiTricity has been scientifically proven not to be harmful and
has been designed to comply with applicable safety
standards and regulations.
How efficient is WiTricity?
WiTricity have only about 40-45% of efficiency.
The efficiency of WiTricity is based on distance between the
source coil and the load coil.
And it is mainly based on the resonating frequency of the
Applications of WiTricity:
Haier wireless TV
Using the wireless and efficient transmission technology
to good effect, Haier has developed a completely wireless
HDTV. Employing WiTricity and Wireless Home Digital
Interface (WHDI), the HDTV is made to stream videos over
100 feet. That’s some distance, when you’re talking of no
wires at all.
Haier’s WiTricity TV
Automatic car charging technology
Toyota and WiTricity to develop new wireless charging
tech that requires no contact and WiTricity’s current
technology is comparable to standard Level to fast charge
technology, providing up to 3.3 kilowatts of power.
WiTricity Charging tech
Advantage of WiTricity:
WiTricity is consider as Safe, fairly efficient, good range.
Magnetic fields interact weakly with biological masses
(humans), Theoretically one stationary coil in a room could
power multiple devices with receiving coils. No more messy
wires, and with widespread enough use it could even
eliminate costly batteries.
The transmission of power without wires is not theory or
a mere possibility, it is now a reality. The electrical energy
can be economically transmitted without wires to any
The system would reduce the cost of electrical energy
used by the consumer and get rid of the landscape of
wires, cables, and transmission towers. It has negligible
demerits like reactive power which was found insignificant
and biologically compatible.