Group 01:

Abbey Reisz, Matt Zapalac, Kymberly Juettemeyer, Cassy Diamond, Joshua Aguilar

Metamaterials: It’s In Your Head!

Primary Article: Planar Photonics with MetasurfacesSecondary Articles: History of Metamaterials, From Metamaterials to Metadevices, Infrared Metamaterial Phase Holograms

Fantasy “Invisibility Cloak “ from Harry Potter franchise

Real world “Invisibility Cloak” using metamaterials

Summary of Research• What are metamaterials?

Why are they relevant?

• History/Background

• Core Concepts/How They

Work

• Applications

• Assessment of

Metamaterials

• ConclusionsNegative index metamaterial array configuration, which was constructed of copper split-ring resonators and wires mounted on interlocking sheets of fiberglass circuit board.

Picture:

MetamaterialsGoogle.com

What are “metamaterials”? Why are they unique?

• Material that gains properties from its surroundings

rather than composition of material

• “Magnetoelastic” material-have a mechanial degree

of freedom that allows mutual interaction with its

surroundings to enable electromagnetic forces to

change the structure and tune its properties; they

respond to light, acoustic waves, and heat flow.

• Negative permeability, permittivity, refractive index,

which are usually positive in other materials

• Reduced dimensionality and bulk; planar, ultrathin

• Controls light waves, acoustic waves, heat waves

• Regular material constraints lifted

The 8 V-shaped prongs represent one unit cell that repeats through the structure; these help demonstrate negative

refractive index and reflection angles that give the material its unique physical and optical properties.

Research and Picture:

Planar Photonics with MetasurfacesAlexander V. Kildishev et al.Science 339, (2013);DOI: 10.1126/science.1232009http://www.sciencemag.org

History/Background of Metamaterials

• What is light? • Magnetic field wave and

electric field wave propogating perpendicular to one another; metamaterials are affected by light, which is electric and magnetic waves.

• James Maxwell-made the

connection between light,

electricity, and magnetism in

the 1800’s; electromagnetic

field

Research:

History of MetamaterialsReed Business InformationJanuary 8, 2011http://www.tmcnet.com

Top Picture

http://www.astronomynotes.com

Research

History of MetamaterialsWikipedia.com

A magnetic and electric

wave propagating together to create an

electromagnetic wave.

Ordinary electrical charges

produce field lines that spread to infinity in

empty space.

Bottom Picture

Electromagnetic FieldGoogle.com

History/Background of Metamaterials

• Victor Veselago-discovered

negative refractive index in

1967

• Electric and magnetic fields

aligned in opposite directions;

the reversal of Snell’s Law would

“bend light the wrong way”

• “Meta” means “beyond”, which

was given as a name to this

material because it is “beyond

conventional materials” Victor Veselago’s proposal of negative refractive index and negative reflection of light on a metasurface

A diagram of Snell’s Law showing the relationship

between angle of incidence and

refraction. Refraction of light at the interface

between two media of different refractive indices,

with n2 > n1. Since the velocity

is lower in the second medium (v2 < v1), the

angle of refraction θ2 is less than the angle of incidence θ1; that is, the ray in the higher-index medium is closer

to the normal.

Research:

History of MetamaterialsReed Business InformationJanuary 8, 2011http://www.tmcnet.com

Top Picture

Snell’s LawWikipedia.com

Research

History of MetamaterialsWikipedia.com

Bottoms Pictures:

Planar Photonics with MetasurfacesAlexander V. Kildishev et al.Science 339, (2013);DOI: 10.1126/science.1232009http://www.sciencemag.org

History/Background of Metamaterials

• John Pendry • Discovered that radiation absorption does not come

from the chemical or molecular structure, but comes from carbon fiber shape within material.

• Discovered negative permittivity and permeability

• Created the “split ring structure” with repeating thin wire structures sequentially.

• David Smith-created the first metamaterial

in 2000 capable of bending electromagnetic

radiation; went on to create first invisibility

cloak.

• Today, we have “active “ metamaterials that

control and respond to surroundings.Top: Split ring structure before the electromagnetic field is appliedBottom: Electromagnetic field applied; lattice parameters change. Research:

History of MetamaterialsReed Business InformationJanuary 8, 2011http://www.tmcnet.com

Research

History of MetamaterialsWikipedia.com

Bottom Picture

Planar Photonics with MetasurfacesAlexander V. Kildishev et al.Science 339, (2013);DOI: 10.1126/science.1232009http://www.sciencemag.org

Core Concepts: Electromagnetics• Light is a direct result of electric

and magnetic waves

propagating together.

• Permittivity and Permeability

must be simultaneously negative

for a metamaterial to exist.

• Permittivity:• The measure of how an electric field

interacts with a dielectric medium.

• Electromagnetic Permeability: • The measure of the ability of a

material to support its own magnetic field.

Research:

PermittivityPermeabilitiyWikipedia.com

Pictures:

Fundamentals of Materials Science and EngineeringCh. 19

An electromagnetic wave showing electric field Є and magnetic field H components and the wavelength λ.

The spectrum of electromagnetic radiation; metamaterials are not visible

to the human eye and the waves absorbed by metamaterials are typically

found in the microwave and infrared region, although all waves are a form of

electromagnetic radiation.

Energy of particle of light is

proportional to frequency by

Planck’s Constant.

Core Concepts: Refractive Index• Refractive Index (n)

• Describes how light propagates through a medium.

• Less than 1

• Can be positive…(normal materials)

• Or negative (metamaterials)

• Wave front can travel towards direction of source

• A video showing negative refractive index:

http://upload.wikimedia.org/wikipedia/commons/c/c7/Negative_refraction.ogg

Refractive index: speed of light over the phase velocity of a given substance. Є is

permittivity and μ is permeability; in order for refractive index to be negative, both of the

others must also be negative.

Research

Negative Index MetamaterialsWikipedia.com

Research and Picture

Using Metamaterials to Defy Our Common Understanding of Lighthttp://www.rikenresearch.riken.jp

Illustration of a negative refractive index

Core Concepts: Acoustic• Inherent parameters of the

medium are the mass

density ρ, bulk modulus β, and

chirality k. • Chirality determines the polarity

of wave propogation.

• Requires negative bulk

modulus and mass density;

these must be altered to define

the refractive index of a

material. • Bulk modulus is the resistance to

uniform compression.

• Allows unique effects such as a

inverse Doppler effect

Research

Double-negative acoustic metamaterialJensen Li and C. T. Chan Science 339, (2013);DOI: 10.1103/PhysRevE.70.055602http://pre.aps.org

Bulk modulus: A diagram of uniform compression. This is possible through negative refractive index and chirality

of metamaterials. Negative bulk modulus means that the medium expands when experiencing compression, and accelerates to the left when being pushed to the right.

The relationship between refractive index (n), mass density (ρ) and bulk modulus (β).

Further Research and Pictures:

Acoustic MetamaterialsWikipedia.com

Applications of Metamaterials: Invisibility • Negative refractive index is

crucial

• Makes the path of light quicker

around an object rather than

through it

• Bend electromagnetic waves

around an object, rendering it

invisible.

• “Perfect” invisibility not yet

possible, but partial invisibility

(translucency) is proven.

Research:

How Invisibility Cloaks WorkWilliam Harris and Robert LambHowstuffworks.com

Diagram:

Super-TechnologiesTheonematrix.com

A diagram of how light (microwave source) affects

normal objects and metamaterials differently.

Photo:

“Is the Army Testing an Invisible Tank?”Alexander Nemenov/AFP/Getty Imageshttp://www.howstuffworks.com/invisible-tank1.htm

Potential to create an armor for soldiers that would render them and their shadows invisible.

Applications of Metamaterials: Invisibility

• Allows:• Invisibility cloaks

• Stealth paint on planes

• See through gloves for surgeons

• Take away blind spots for drivers in cars

• Virtually anything in the military ranging from clothes for soldiers to invisible planes

Pictures:

Google.com

A person wearing a real “invisibility cloak” made of metamaterials

The type of plane that would benefit from metamaterial cloaking; stealth attacks and landing would be much

easier and safer.

Applications of Metamaterials: Subwavelenth Imaging and Superlenses

• What is a superlens?• Goes beyond diffraction

limit• Most lenses limited by

imperfections

• Superresolution

• Microwave frequencies

Research:

From metamaterials to metadevicesNikolay I. Zheludev and Yuri S. KivsharNature Materials 11, 917-924 (2012)DOI: 10.1038/nmat343123 October 2012

Research:

SuperlensWikipedia.com

• Subwavelength images via metamaterials allow to see cells in real time in natural environment

• Can see patterns which are too small to be seen by conventional microscopes

Top Picture:

The SuperlensNature.com

Bottom Picture:

Google.com

An example of how molecules would look with subwavelength imaging.

Applications of Metamaterials: Wireless Power Transmission • Metamaterial is placed between

the transmitter and the receiver

would create a kind of lens,

directing the energy so that

most of it gets to the device

being charged.• This metamaterial would use

thousands of individual thin conducting loops that would be tailored to recipient device.

• Space between the charger and

chargee effectively disappears.

• Short range mobile devices are

an easy feat, but electric

vehicle charging and more is a

new possibility.• Perhaps the device could be created

inside the car to self-charge anywhere.

Research

Metamaterials: Wireless PowerGizmag.comNoel McKeeganMay 25, 2011

Research

Artificially Structured Metamaterials May Boost Wireless Power TransferSciencedaily.comMarch 12, 2012

How the charging cycle works through the flow of electricity and wireless power.

Current electric automobile charging device; can someday have the charger at a further distance.

Pictures

Wireless Charging MetamaterialsGoogle.com

Applications of Metamaterials: Holographic Images• Artificial structuring is represented by

diffractive optics, which control a wave through

multilevel diffractive devices.

• Gerchberg-Saxton iterative algorithm • Relationship between complex transmittance and of

the hologram and the far-field image generated

• Iteratively adjusts the constraints in the hologram and the image to focus.

• Metamaterials are crucial for holographic

images because of the metal inclusions that

are strong scatterers of electromagnetic waves

and provide a large electric polarization.• Provides a magnetic response and controlled

anistrophy (directional dependence of waves)

Process Flow for the fabrication of the

multilayer metamaterial

hologram

Research and Photo:

Infrared metamaterial phase hologramsStephane Larouche, Yu-Ju Tsai, et al.Nature Materials 11, 450-454 (2012)DOI: 10.1038/nmat327818 March 2012

Artistic rendering of a section of metamaterial hologram demonstrating the various metamaterial elements used. The hologram consists of three layers of gold elements in a SiO2 matrix over a Ge substrate. 

Photo: Rendering

“Infrared metamaterial phase holograms”http://nextbigfuture.com/2012/03/infrared-metamaterial-phase-holograms.html#more

Applications of Metamaterials: Holographic Images • Could render perfect holograms

on a 2D display.

• So accurate that you can look

into it with binoculars and still

not be able to tell it’s a

holographic image.

• Infrared region (10.6

micrometers)

• Can be applied to videogames,

television, military, graphics in

general

Research:

Infrared metamaterial phase hologramsStephane Larouche, Yu-Ju Tsai, et al.Nature Materials 11, 450-454 (2012)DOI: 10.1038/nmat327818 March 2012

A fantasy hologram from the Star Wars franchise; an idea of how holograms could eventually look.

Duke University’s metametarials hologram; the E was not formed due to grazing incidence.

Bottom Picture:

Nature.com

Top Picture:

Google.comHolograms

Applications of Metamaterials: Terahertz Biosensors

• Can identify a chemical or

biochemical molecular

composition even very

minute amounts

• Increased sensitivity and

facilitated readout

• Sense the dielectric

properties of a sample in

the terahertz frequency

range

Research and Picture:

Metamaterials Application in SensingTao Chen, Suyan Li, Hui Sunwww.mdpi.comDOI: 10.3390/s12030274229 February 2012

(a) Schematic of the micrometer-sized metamaterial resonators sprayed on paper

substrates with a predefined microstencil; (b) Photograph of a paper-based terahertz

metamaterial sample; (c) Optical microscopy image of one portion of a paper

metamaterial sample.

Applications of Metamaterials: Biosensors

• Biosensors : disease

diagnostics, environmental

monitoring, food safety, and

investigation of biological

phenomena

• Used to improve the sensor

selectivity of detecting

nonlinear substances

• Can improve the mechanical,

optical and electromagnetic

properties of sensors

Research

Metamaterials Application in SensingTao Chen, Suyan Li, Hui Sunwww.mdpi.comDOI: 10.3390/s12030274229 February 2012

• Need for bioanalytical sensing techniques that can directly detect the target molecules without labeling

•Technologies based on metamaterials provide cost-efficient and label-free biomolecule detection

Image:

"Biosensing Using Gold Nanorod Metamaterials." All About Biosensors. N.p., n.d. Web. 06 Apr. 2013.

Allows to detect analytes (biomolecules) in volumes down to attoliters; single particle

measurements probe the local environment around one specific particle.

TEM micrographs of gold nanorods with mean aspect ratio

2.8.

Applications of Metamaterials: Communication• Need to keep the antenna size

within specific size or foot

print

• Metamaterials used to

minimize surface waves

arising from micro strip patch

antennas

• Goal: Increase the gain of the

micro strip antenna while

maintaining its low attractive,

low profile features

Research

Metamaterials Application in SensingTao Chen, Suyan Li, Hui Sunwww.mdpi.comDOI: 10.3390/s12030274229 February 2012

• Magnetic superstrates that use split ring resonators (MSRR) inclusions

• The MSRR unit cell is to have POSITIVE values for the effective permeability and permittivity at the resonance frequency of the antenna

Shows the gain of the micro strip antenna before and after using the

artificial magnetic superstrate. The gain improved by 3.4 dB at the resonance frequency after using the engineered

superstrate. This means the efficiency of the antenna at the operating frequency of 2.2GHz increased by 17% due to the

metamaterial superstrate.

A planar 10X10 array of MSRRS was printed on the hose dielectric layer to provide the engineered magnetic material. The superstrates used here consists of 3 layers of printed

magnetic inclusions, separated by 2 mm of air layers.

Images :O. M. Ramahi, M. S. Boybay, O. Siddiqui, L. Yousefi, A. Kabiri, Hussein Attia, M. Bait-Suwailam and Z. Ren, "Metamaterials: An Enabling Technology for Wireless Communications," Proceeding of International Conference on Communication Technologies ICCT2010, Riyadh, Saudi Arabia, Jan. 18-20, 2010

Applications of Metamaterials: Superconductors

• Often made of niobium

Research:

From metamaterials to metadevicesNikolay I. Zheludev and Yuri S. KivsharNature Materials 11, 917-924 (2012)DOI: 10.1038/nmat343123 October 2012

Top Picture

Periodictable.com

Bottom Picture:

Terahertz nonliner superconducting metamaterialApl.aip.org

• Limited to microwave and terahertz spectral domains

• Switch from plasmonic excitations to quantum excitations

• Can control magnetic fields• Provide lower losses with better

sensitivity

Diagram of a terahertz metamaterial superconductor.

Periodic table data for Niobum

Assessment of Metamaterials• Cost efficient

• Low cost manufacturing

• Less bulky, planar structure

• Can affect many different types of

waves: optical, acoustic, heat,

infrared, magnetic field, electric

• Unlimited combinations with other

materials

• Unlimited possibilities with a

structure that adapts to external

stimuli

Picture:

Google.com

A man wearing a metamaterial shirt that allows him to appear

translucent.

Metamaterials with unique mechanical properties. A team there has designed materials with

“negative compressibility” that in theory will compress when they are pulled and expand when

they are compressed.

Picture: Mechanical Properties

“New ‘Mechanical Metamaterial’ Expands When You Compress It, Shrinks When your Stretch It”http://www.popsci.com/technology/article/2012-05/new-mechanical-metamaterial-expands-when-you-compress-it-shrinks-when-you-stretch-it

Further Suggested Research• Other applications

• Future applications

• Integration/hybridization of metamaterials with natural

materials

• How to improve metamaterials

• Commercial uses

• More capabilities of metamaterials

Picture: nature.com The many different types of

metamaterials

Conclusions• Negative refractive index can

change the structure of

metamaterials

• Electricity, magnetism, light,

heat can all affect a material

• Structures can change based on

surroundings

• Main applications include the

super-lens and invisibility cloak,

but open doors to many other

fields and possibilities.

Picture: MetamaterialsGoogle.com

A metamaterial that could allow wireless power transmission.