Meta materials are advance materials with negative refractive index, they show excellent applications like cloaking effect, super lens, WMD detectors also flying doughnut etc. They are very futuristic . This presentation explains the basic definition, history, scientific principle and its applications etc.

1. Meta-Materials
Presented by- 1. Tanmay Padwal 19CHE220
2. Dhiraj Sutar 19CHE207

2. Introduction
Meta (from the Greek word μετά ) - beyond.
Metamaterials are new artificial materials with unusual
electromagnetic properties that are not found in
naturally occurring materials.[1]
Materials which extract their properties from their
structure rather than materials of which the are
composed of[2]

3. n= Index of refraction
c= speed of light in vacuum
v= speed of light in medium

4. Negative refractive index

6. 1.Concept of Metamaterials was first introduced in
1968 by soviet physicist V.G. Veselago.
He said “materials with both negative permittivity and
negative permeability are theoretically possible”.[3]
2.John Pendry identified a practical way to make metamaterials.
He proposed his design of periodically arranged Thin-Wire (TW)
structure that depicts the negative value of effective permittivity.
[2]
V.G. Veselago
History

7. Negative refractive index

8. Classification of materials

9. Double positive (DPS) materials
The materials which have both permittivity & permeability greater than zero (ε > 0, μ >
0) are called as double positive (DPS) materials.
Most occurring media (e.g. dielectrics) fall under this designation.
The forward propagation of wave takes place in first quadrant.
It follows Right hand thumb rule for direction of propagation of wave

10. Epsilon negative (ENG) materials
If a material has permittivity less than zero and permeability greater
than zero (ε < 0, μ > 0) it is called as epsilon negative (ENG)
material. Eg. Plasmas

11. Mu negative (MNG) materials
If a material has permittivity greater than zero & permeability
less than zero (ε > 0, μ < 0) it is called as mu negative (MNG)
material. This also support evanescent waves.

12. Double negative (DNG) materials
The third quadrant ε<0, μ < 0 represents materials, also called left handed
materials. It follows the left hand rule because propagation of wave takes
place in backward direction in this medium.
Due to negative ε and negative μ, the refractive index of the medium is
calculated to be negative. Thus termed as NIM (negative index materials).

13. Split ring resonators

14. Special effects shown by Metamaterials
1. Reverse doppler effect
2. Reverse Cherenkov effect

15. Reverse doppler
Another strange property of metamaterials is the reverse Doppler
effect.
It makes a train-whistle sound higher in pitch as it approaches and
lower in pitch as it recedes. The possible application for such
phenomenon is in mobile wireless communication and is still under
investigation.

16. Reverse Cherenkov effect
Charged particle passing through a medium emits light
from a cone behind the particle rather than in front of it as
in “normal” materials.
Cherenkov radiation occurs when a charged particle
moves in a material with a speed faster than light. In
particle physics, one possible application is constructing a
Cherenkov detector to identify charged particles of various
velocities.

17. Reverse chernkov effect

18. Metamaterials as combination of different material
properties
1. With conventional materials, we are stuck with the
properties of materials being same everywhere.
2. With metamaterials, we can put different material
properties in each of the squares shown in the
figure.
3. The materials are arranged in repeating patterns, at
scales that are smaller than thewavelengths

19. Applications of Metamaterials
Superlens
Absorber
Cloaking
WMD detectors
Flying
Antennas

20. Metamaterials in optics : “Super” lens
John B. Pendry, a physicist at the Imperial College London, has claimed that lens made of
metamaterials could focus light for objects less than wavelength λ in size to a geometric
point. All lens utilizing natural materials known today cannot focus light onto an area smaller
than the square wavelength of the light used to examine it (the diffraction limit).
Sub-wavelength resolution, or focusing beyond the diffraction limit, is possible with a perfect,
flat lens made up of metamaterials.
In optics, every lens made has been limited by the wavelength of the light it uses to focus
until now. With metamaterials, a “super” lens that can focus on features smaller than the
wavelength of the light itself should be possible.
The electrical permittivity ε (response to an electric field) and the magnetic permeability µ
(response to a magnetic field) are the main determinants of a material’s response to
electromagnetic (EM) waves

21. Super resolution imaging

22. The supermicroscope

23. Metamaterials as absorber
❖ Research is being done for the design of thin electromagnetic
absorbers. 11.5GHz the experimental absorptivity of 88% (Landy
2008)
❖ This absorbers can operate in microwave , terahertz and even in
visible frequencies.
❖ Electromagnetic wave absorber: A device which absorb all
incident radiation at the operating frequency.
❖ Metamaterials have allowed for the development of a perfect
absorber

24. Metamaterial absorber
A single unit cell of the absorber consisted of two distinct
metallic elements as shown in fig. Electric coupling was
supplied by the electric ring resonator (ERR) shown in
fig. (a). This element consisted of two standard split ring
resonator connected by the inductive ring parallel to the
split wire.
(a) ERR, (b) cut wire, (c) axis shown with
propagation direction

25. Metamaterial Cloaking
❖ Metamaterials direct and control the propagation and
transmission of specified parts of the light spectrum and
demonstrate the potential to render an object seemingly
invisible.
❖ Objects in the defined location are still present, but incident
waves are guided around them without being affected by the
object itself

26. Cloaking effect

27. Applications : Invisible submarines
To make submarine invisible to enemy sonar, it bends
sound around it and this program is funded by Russian
Naval Research.
The findings showed that the
waves reflected from the
metamaterial matched the
phase of the reflected wave of
the surface. Additionally, the
amplitude of the reflected
wave from the cloaked object
decreased slightly.

28. Metamaterials as Weapon of Mass Destruction
Detectors
1. Army researchers are using metamaterials to build biological-
and chemical-agent detectors.
2. Metallic nanostructures in metamaterials react
electromagnetically to incoming molecules, revealing their
identities through a variety of responses.
3. This method can detect single molecules, which could be of
great use for passenger or cargo screening.
4. Availability: Possibly as little as five years for a working
prototype.

29. Metamaterials for flying
1. A proposed scheme for generating torus-shaped light pulses called
flying doughnuts utilizes a metamaterial “sprinkled” with tiny
resonators in a concentric ring pattern.
2. Electromagnetic waves are typically transverse, which means their
electric and magnetic fields point perpendicularly to the direction of
wave propagation.
3. Certain electromagnetic waveforms have longitudinal field
components that are parallel to the propagation direction.
4. One example is the flying electromagnetic doughnut, whose fields
wrap around in a torus pattern. Such pulses could potentially transfer
information, accelerate particles, or perform spectroscopy

30. Flying Doughnut

31. Metamaterials as Antenna
1. An antenna is an arrangement of two or more conductors usually
called elements.
2. At transmitter of antenna, an alternating current is created in the
elements which radiate electromagnetic field.
3. In reception, reverse occurs.
4. Advantages: Small size, Increased directivity , Step up radiated
power by impedance matching.

32. Applications of MM antennas
1. High speed Wireless communication (Wifi)
2. Space communications
3. GPS
4. Satellites
5. Space vehicle navigation

33. Application-Super cellphones
1. Although they measure just a few millimeters long and are as flat as paper,
the new multiband antennas could double the range, reliability and battery
life of cellular phones, Wi-Fi routers and wireless modems.
2. Availability: Already for sale, but the quality is expected to steadily improve
over the next five years.
3. LG chocolate BL 40 is using metamaterial antennas.

34. References
1. A brief intro to metamaterials IEEE Author : R.S. Kshetrimayum
2. Negative refraction ,Contemporary Physics: J. B. PENDRY
3. A Review of Metamaterials and its Applications:Gurwinder Singh, Rajni, Anupma Marwaha
4. ,Metamaterials: Fundamentals and Applications in the MicrowaveandOpticalRegimes
By GEORGE V. ELEFTHERIADES
5. A Review of Metamaterials and its Applications Gurwinder Singh , Rajni, Anupma Marwaha
6. The century of metamaterials to cite this article: Sergei Tretyakov
7. Hybridization effect in coupled metamaterialsHui Liu, Tao LI, Shu-ming Wang and Shi-ning Zhu
8. A Study of Significance of Metamaterial in Antenna Array Elements DesignNeha Singh, Kamal Kishor
Choure, Amandeep Kochar
9. Metamaterial Antennas and Applications- A Review Jaget Singh
10. Metamaterials: Characteristics, Process and Applications Kaushal Gangwar , Dr. Paras and Dr. R.P.S.
Gangwar
11. A review paper on Techniques and Design for metamaterialsRekha Chahar , Neelam singh

35. Thank you