Materials & Devices of Future: Challenges associated with Trends

SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH19, UNVERSITY ROAD, DELHI - 110 007

Presented By :

Dr. R. K. Khandal

Outline

Materials & Devices: Attributes

Trends in Materials & Devices

Challenges associated with Major Sectors

Energy

Defense

Health

Infrastructure

Materials & Devices: Attributes

Past

Steadiness

Present Future

Productivity

Bulk

Quality

Controls

Surface

Precision

Software driven

Carbon footprint

Strength : weight

Emphasis on life- cycle

Environment friendly

Precision

Selective

Capacity driven

Inclusive

Capability driven

Innovation

Nano

Sensitive & Smart

Materials & Devices: Trends

Materials Devices

Devices

Trends

Applications

Materials

Purpose- SpecificSustainable

SafeEnergy-Efficient

Raw materials

GreenCradle-to-grave cycleEnvironment-friendly

AlternativesRenewable

Trends drive the advent of new materials and new devices in different industry sectors

ENERGY SECTOR

SOLAR ENERGY : CONVERSIONSolar Energy

Electrical (Photovoltics

)Thermal

Ele

ctr

ic E

nerg

y

Th

erm

al En

erg

y

Thermo Chemica

l Process

Ch

em

ical

En

erg

y

Mech

an

ical E

nerg

y

Photon

Solar Thermal; Most exploited : Material & Design specific Solar Chemical; Evolving : Material specific

Electrochemical

Need exist for development of materials and technologies capable of converting solar energy to chemical energy i.e. photochemical conversion

PHOTOCHEMICAL CONVERSIONThe Energy E of single photon is given by the Planck equation:- E=h= hc/

Sun light

.

…….. ...………………………………electron

Excitation photon

excited state

Non-radiative relaxation

Conduction band

Valence band

h+

e-

Band gap

E=h

Every photochemical conversion process requires as an initial step, the absorption of photon energy and formation of the first excited state of the molecule

=Number of events

Number of photons absorbed

Solar Selectivity : Materials Response Frequency (Hz)

Visib

le

Infrared

Ultraviolet

X-rays

Cosm

ic rays

1081010101210141016101810201022

Rad

iofrequ

ency

Gam

ma rays

Microw

ave

High Potential for harnessing the solar energy

Processes involved Inner

electronic transition

Outer electronic transition

Molecular Vibrations

Molecular rotations vibrations

Electron spin resonance

Nuclear magnetic resonance

Change at atomic & molecular levels can become the via media for harnessing solar energy.

Solar sensitive materials undergo region specific transition Solar energy conversion

Energy Efficient Materials

Devices like smart windows can be designed by thin film coatings to create energy efficient buildings

Criteria Requirement Design Materials

Admit light,

reject solar heat

Transmit: 400 to 700nmReflect: 700 to >2500nm

Solar heating

Radiativecooling

Transmit /absorb: <2500nm

Reflect : >2500nm

Emit : >5000nm

TiO2 Bi2O3 Zn/ Cu, Ag,

Au/TiO2 Bi2O3

Al2O3 / MO/

Al2O3

SiO2;oxynitrides

Dielectric/ Metal/

Dielectric layer

Cermet Coating

Oxides

Semiconductor

DEFENSE SECTOR

CAMOUFLAGE : MATERIALS

Scattering Au, Ag, Pd, Ir, Ti Coloration is size dependent, Small

sized particles reflect light chromatically

Interference Metals, Interference Metal oxides between light

reflected from opposite parallel slides

Electronic Carbon Color is due to transition Black electronic transition

MATERIALS PROPERTIES

Selection of dispersing matrix for achieving coloration is the key !

Stealth Application: Metamaterials

= µrr

Metamaterials are engineered to have EM responses which are impossible in naturally occurring materials

1

2

1

2

+ve R.I.

-ve R.I.

Refractive Index

= µrr

µr: Permeability to magnetic field r: Permeability to electric field

µr or r= - ve

Induced phenomena

µr, r= +ve Natural phenomena

Materials for Stealth Applications: Composites

Periodic arrangement of R.I. variation controls movement of photons New energy levels within the band gaps can be created by breaking the

periodicity of the photonic material by enlarging, reducing or removing voids; the desired change in refractive index can be achieved by modifying the voids

Wavelength selective structures can be formed by careful selection of symmetry & spacing

Modification of light propagation takes place through enlarging, reducing or removing voids; optical cross-connects, switches & waveguides

Photonic band gap: Restricts transmission of light to defined set of bands

Voids

Enlarged voids Reduced voids Voids removal

Matrix

HEALTH SECTOR

Health Sector : Drug Delivery

Nanospheres

Nanocapsules

Dendrimers

(Vesicular system)

(Matrix system)

SLN particles(Solid lipid

nanoparticles)

(Macromolecule, comprising of series of branches around an inner core)

Liposomes(Artificial spherical vesicles produced from natural phospholipids & cholestrol)

Polymeric micelles(Amphiphilic block copolymers which self-associate in aqueous solution)

INFRASTRUCTURE SECTOR

Infrastructure Sector : Paints & Coatings

Nanoparticles

Nanoparticles fill the voids created by larger particles in order to prevent water penetration & seal out moisture in the area of water proof coatings

Use of nanotechnology enhances Scratch& Abrasion resistance

UV-Protection

Mechanical properties

Infrastructure Sector : Smart Materials

On exposure to inputs, some materials exhibit change Utilization of such materials is key for green buildings

Thermochromic

Material InputHeat

Electrochromic

Photochromic Radiation (light)

Output

Colour

Electroluminescent Electric potential

Solar Radiation

Heat

LightPhotoluminescent

Thermoluminescent

Piezoelectric Mechanical Force

Heat

Electric potentialShapePyroelectric

Electrostrictive

Magnetostrictive Magnetic potential

Electric Potential

THANK YOU