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Nano-scale Science and Technology: An Overview

Om Prakash Khatri

Nanoscopic Surface Architecture LaboratoryDepartment of Materials Science and Engineering

Kyoto University, Kyoto

14th June 2007

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Nano-scale Science and Technology

“Study of objects, phenomena and/or manipulation of physical system over 1-100 nanometer scale”

1 nm = 10-9 m = One billionth of meter

× 101 nm

Hydrogen AtomDiameter = 0.1 nm

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Comparison Between Human Size and Nano

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How to Correlate the Nano-scaleA. Human Hair

Human hair is 50,000 -80,000 nm wide and grows ~ 10 nm every second

B. Red Blood Cell (RBC)

Diameter of typical human RBC is 6-8 µm.Every seconds 2.5 million RBCs

are destroyed.

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C. Human Immunodeficiency Virus (HIV)

Diameter of HIV virus is 120 nm, which causes AIDS disease

D. DNA structure

DNA is 2.2 to 2.4 nm wide and made from repeating units of Nucleotides

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How Nano is Big: Everything is Changing

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Nano-FabricSatin and Oil Resistance, Anti-UV and Anti-Microbial

Fabric processed through nanotechnology like self assembly of either different molecules or nano-colloids, provides unique properties.

Nano-MaskSilver Nanoparticles in fiber reduces odor and bacteria on skin, which helps to keep feet dry and comfortable.

Enhanced filter media to remove Virus and Bacteria

Nano-Socks

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Nano-Cosmetics

Zinc oxide particles: Sun CreamSuperfine Silica Particles: Skin CreamBuckyballs: Prevents premature aging of the skin by acting as antioxidant

Buckyballs

Nano-Sports

Golf: Nano-composite makes the top part of driver more lighter, which helps the golfer to hit with more power and accuracy.

Tennis: Nano-tube makes more stronger and light racket

Bowling: Fullerenes uses as a super-hard coating on bowling balls.

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Baseball BatNano-BandageiPod NanoiPhone

Memory Card

Nano-UmbrellaNano-FabricKey-Chain Digital Camera Nanotech Products are:

LighterStrongerFasterSmallerMore DurableBiocompatible

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How do we build so small: Nanofabrication

Top-down Approach

Construct the nanostructure, starting with a larger component by remove or alter the material

1. Photo Lithography2. Soft Lithography (Micro Contact Printing)3. Scanning Probe based Lithography etc.

Bottom-up Approach

Formation of small devices or nanostructures from molecules or atoms

1. Self assembly process (molecules, colloidal particles etc)2. Carbon Nanotubes etc

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Photolithography

Photolithography is a process, which remove parts of a thin film (or the bulk of a substrate), by light exposure through Photo-mask

1. Light Source: Deep Ultraviolet (DUV) light below 300 nm wavelengths

2. Minimum Pattern Size: 100 nm

3. Mass Production

Gold Nanoparticles arrays

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How we makes Photo-pattern1. Clean the substrate

Silicon

Silicon oxide

4. Unexposed molecular Film

Silicon2. Formation of molecular Film

5. Oxide film etched away from Hydrofluoric acidSilicon

Silicon

3. Silicon is exposed to UV light through Photo-mask

UV Radiation

Photo-mask

Silicon

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Soft Lithography (Micro Contact Printing)

1. Efficient methods for the duplication of the shape and morphology from the mold surface at micro to nano-scale

2. The stamps are made from poly(dimethyl)siloxane(PDMS)

3. Lower cost than traditional photolithography 4. Mass production 5. Well-suited for applications in Biotechnology6. Smaller pattern size than photolithography

(~30nm vs ~100nm)

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Soft Lithography

Fluorescence microscopy images of arrays of (A) 10 um, (B) 5 um spots of Texas-Red labelled Streptavidin/Biotin complex by micro-contact printed on poly(methyl methacrylate)

Micro-contact printing, in which a weakly bound film is displaced by contact stamping with molecules

that bind more strongly to the substrate

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Dip Pen Lithography

AFM tip is used to deliver molecules to a surface via a solvent meniscus. This direct-write technique offers high-resolution patterning capabilities for a number of molecular and bio-molecular or colloidal ink and they forms a self assembled monolayer. Sub-100nm length scale features are fabricated by this method.

Courtesy: Prof. C. Mirkin Group

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Self Assembled Monolayer

“A two-dimensional film, one molecule thick, covalently organized or assembled at an interface”

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Why self assembly system is important

1. Reduces the Friction and Adhesion: Lubrication engineering

2. Chemical Biological Sensors

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3. Patterning

A patterned SAM with alternating COOH-terminated and CH3 stripes

4. Wettability

Hydrophobic

Hydrophilic

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Carbon Nanotubes

“Allotropes of Carbon”

Single Wall Nanotubes are one atom thick sheet of graphite rolled up into a seamless cylinder with diameter of the order of a nanometer.

Multi Wall Nanotubes consist of multiple layers of graphite rolled in on themselves to form tube shape

The strength and flexibility of carbon nanotubes makes them of potential use in Nanotechnology

Carbon Nanotubes Make The Space Elevator Possible ????

Carbon Nanotube Tips

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Nanoparticles

The chemical properties (reactivity, flammability, etc.) and the physical properties (melting point, conductivity, optical property etc.) all changes at the nano-scale. Size-dependent properties are the major reason, that nano-scale objects have such amazing potential.

m.p. bulk

1000

Tm

eltin

g(°

C)

500

00 5 10 15 20

Gold Nanoparticles Particle Diameter (nm)

Melting point of gold as a function of gold particle diameter

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Optical Properties of Nanoparticles

Gold particles have different colors depending on size and shape

Gold Nanoparticles distribution

Gold

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Scanning Probe Microscope“Image of the surfaces using a physical probe that scans the specimen”

1. Atomic Force Microscopy

“Measure the surface features due to atomic force interaction between tip & sample”A. Contact AFM,B. Non-contact AFM and C. Dynamic contact AFM

2. Scanning Tunneling Microscopy

“Detect a weak electric current flowing between tip and the surface”

3. Magnetic Force Microscopy

“Magnetic interaction between tip and samples”

4. Kelvin Force Microscopy

“Work function or chemical contrast of surfaces can be observed at nano-scales”

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How AFM Works

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What information, we gets from SPM

Surface Roughness at Atomic level (Topography)

AFM friction: NaCl (100)

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3. Biological Features

Butterfly wing

4. STM atomic resolution on HOPG (Highly Oriented graphite with atomic resolution)

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Nanoflower grown by deposition of antimony on a smooth carbon surface

Atomic Resolution on Si (111); 5.4nm x 5.4nm

Enzyme-substrate Interactions

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To Measure Adhesive Force for Biological Systems

By pulling on fimbriae with the tip of an AFM, provides mechanical properties that helped to elucidate their function.

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Nanotechnology in Biological Systems

1. Hip Implant Materials

Nano-scale modification of implant surfaces would improve implant durability and biocompatibility

2. Nano-Robots

The nano-robot is using rotary blades to break up the blockage and sucking the fragments into nozzles

Nano-Robot swimming through human vein

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Why Learn about NanoWhy Learn about Nano--scale Science and Technology in scale Science and Technology in High Schools ?High Schools ?

Important and challenging to know about

recent developments in Nanotechnology and

its impact on daily life.

Very multi-disciplinary (physics, chemistry,

biology, mechanics, electronics, materials...).

Critical for future of science.

Important societal and ethical issues.

Can motivate students to go for science

and engineering.

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Few words about India

Population: 1100 millionArea: 3,287,890 sq. kmLanguages: Hindi, English and

18 regional languagesStrong Facts: Tourism, Information

Technology etc.

Population: 128 millionArea: 377,835 sq. kmLanguages: JapaneseStrong Facts: Electronics, Automotive

industries etc

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India

The Indus Valley civilization, one of the oldest in the world

28 States and 7 Union Territories

National Capital: Delhi

Literacy: 61%

Government: Federal Republic

Religions

1.9%1.9%2.3%

13.4%

OthersSikh

Christian

MuslimHindu

National Costume: Sari (Women)National Bird: PeacockNational Fruit: Mango

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India: Tourism Facts

Tajmahal, Agra“One of the Beautiful Wonder of the world”

Rishikesh, Holy city for Hindus located in the foothills of the Himalaya

Lake Palace, UdaipurWonderful beaches: Lakshadeep

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India: Tourism Facts

Mumbai: Gate of India Kerala: House Boat

The Bengal Tiger(India has largest population in the world)

Hawa Mahal (Place of winds), Jaipur

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India: Cultural FactsIndian Dances

Indian Women

KashmirRajasthan Punjab

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Indian Education System

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LKG, UKG(Age: 3-5)

Class 1-5(Age: 6-11)

Class 6-10(Age: 11-16)

Class 11-12(Age: 16-18)

Nursery Primary Secondary Higher Sec

Engineering: 4 Years

Medical: 5 Years

Science: 3 Years

Commerce: 3 Years

Arts: 3 Years

Master Degree(2-3 years) Research: Ph.D.Higher Secondary

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“ELEMENTARY EDUCATION IS FUNDAMENTAL RIGHT FOR EVERY CHILD IN INDIA”

Indian culture is in the core attributes of education beginning from GURUKUL type of education, where the disciples lived in the house of master who taught them.

IndianEducation

System

931500Schools45000

Colleges

300U

niversities

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Elementary Schooling

All children should complete eight years elementary schooling: Government of India

Modern Elementary Schools

School fee are very high compared to Government schools

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High School Education

High School Education is very important to decide Future Goals.Subjects Specialization starts from High Schools. Like Science, Arts, Commerce etc

College/University/InstituteEntrance Examination

And/orDirect Merit Basis

High Schools

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Higher EducationOver 300 UniversitiesCovers all disciplines like Science, Engineering, Medical, Pharmaceuticals, Agriculture, Managements, Humanities, Commerce, Dairy & Fisheries and Fashion designing etc Tough competition to get admission in Good University/InstitutesMost of Universities or Institutes are Funded by Government. Pune University

Indian Institute of Technology, Roorkee

Indian Institute of Science, Bangalore

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Acknowledgment

JSPS (Japan Society for the Promotion of Science) for this opportunity.

&

Prof. K. MuraseProf. H. Sugimura

Nanoscopic Surface Architecture Laboratory,Material Science and Engineering Department

Kyoto University, Kyoto

* Most of Information are collected from public domains.

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THAN

KS...

.

khatriopk@gmail.com