introduction to nanoscience and nanotechnology

Introduction to Nanoscience and Nanotechnology

Dr. Bharat ParekhSchool of Technology

Pandit Deendayal Petroleum UniversityGandhinagar-382007

Gujarat, India

Pandit Deendayal Petroleum University

Plan of the Talk

• Nanoscience-Definition• Background• Lesson from Nature• Building nano structures• Synthesis of nanomaterials (CdTe)• Applications in different field• Nano Industry• Summary

• A biological system can be exceedingly small. Many of the cells are very tiny, but they are very active; they manufacture various substances; they walk around; they wiggle; and they do all kinds of marvelous things—all on a very small scale. Also, they store information. Consider the possibility that we too can make a thing very small that does what we want—that we can manufacture an object that maneuvers at that level.(From the talk “There’s Plenty of Room at the Bottom,” delivered by Richard P. Feynman at the annual meeting of the American Physical Society at the California institute of Technology, Pasadena, CA, on December 29, 1959.)

Introduction

What is Nanoscience?

When people talk about Nanoscience, many start by describing things

• Physicists and Material Scientists point to things like new nanocarbon materials:

• They effuse about nanocarbon’s strength and electrical properties

Graphene Carbon Nanotube C60 Buckminster Fullerene

"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience


Biologists counter that nanocarbon is a recent discoveryTHEY’VE been studying DNA and RNA for much longer(And are already using it to transform our world)


And Chemists note THEY’VE synthesized molecules for over a century

<= First OLED material: tris 8-hydroxyquinoline aluminum(OLED = organic light emitting diode)

Commercial OLED material: Polypyrrole

Most heavily investigated molecular electronic switch: Nitro oligo phenylene ethynylene


All of these things ARE very small

Indeed, they are all about the size of a nanometer:Nano = 10-9 = 1/ 1,000,000,000 = 1 / Billion A nanometer is

about the size of ten atoms in a row

This leads to ONE commonly used definition of nanoscience:Nanoscience is study of nanometer size things (?)

Why the question mark? Because what is so special about a nanometer?

A micrometer is ALSO awfully small: Micro = 10-6 - 1/1,000,000 = 1 / Million

A micrometer (or "micron") is ~ size of light's wavelength


And microtechnology has been rolling along for half a century!

Microelectronics = Integrated circuits, PC's, iPods, iPhones . . .

Intel 4004: The original "computer on a chip" - 1971 (Source: UVA Virtual Lab)

Also = MEMS (Micro-electro-mechanical-systems): Air bag accelerometers, micro-mirror TVs & projectors . . .

(Source: Texas Instruments DLP demo - www.dlp.com/tech/what.aspx)


Indeed, microtechnology has gotten smaller EVERY year

MOORE'S LAW: The (then almost whimsical) 1965 observation by Intel co-founder Gordon Moore that the transistor count for integrated circuits seemed to be doubling every 18-24 months

He was really sticking his neck out: IC's had only been invented 7 years before!(by Moore, his Fairchild/Intel colleagues, and Texas Instrument's Jack Kilby)

But his "law" has since been followed for forty five years:

(Source: www.intel.com/technology/mooreslaw/index.htm)


So is Nanoscience/technology really new & unique?

• Micro is also VERY small• Micro has been around for a long time• Micro has steadily shrunk to the point that it is now

almost NANO anyway !• Leading to a LOT of confusion about the distinction

between Micro & Nano • Even among scientists!!• And likelihood that Nanotechnology will be built UPON

Microtechnology• Either by using certain Microfabrication techniques Or,

literally, by being assembled ATOP Microstructures


Meaning that the NANO "revolution" is just a lot of hype?

Just about making things incrementally smaller?Just about a simple shift in the most convenient unit of

measure?I DO see something very unique about Nano:

Nano is about boundaries where BEHAVIOR radically changes:

When the BEHAVIOR OF THE OBJECTS SUDDENLY CHANGES

Or when OUR BEHAVIOR MUST CHANGE to make those things


Boundary :ELECTRON WAVES Separate NanoSCIENCE from MicroSCIENCE

The discovery that electrons = waves led to QUANTUM MECHANICSA weird, new, counter intuitive, non-Newtonian way of looking at the nano world With a particular impact upon our understanding of electrons: Electrons => Waves

How do you figure out an electron’s wavelength?electron = h / p

“De Broglie’s Relationship”( = electron wavelength, h = Planck’s Constant, p = electron’s momentum)

This relationship was based on series of experiments late 1800’s / early 1900’s

To put the size of an electron’s wavelength in perspective:

Nanometer Scale - Unknown Behavior

• “Magical Point on Length Scale, for this is the point where the smallest man-made devices meet atoms and molecules of the natural world.” – Eugene Wong, Knight Rider Newspapers, Kansas City Star, Monday Nov.

8th, 1999

• Just wait, the next century is going to be incredible. We are about to be able to build things that work at the smallest possible length scales, atom by atom . These little nanothings will revolutionize our industries and our lives.”– R. Smalley, Congressional Hearings, Summer 1999.


Size of ThingsMillimeters Microns Nanometers

Ball of a ball point pen 0.5

Thickness of paper 0.1 100

Human hair 0.02 - 0.2 20 – 200

Talcum Powder 40

Fiberglass fibers 10

Carbon fiber 5

Human red blood cell 4 – 6

E-coli bacterium 1

Size of a modern transistor 0.25 250

Size of Smallpox virus 0.2 – 0.3 200 – 300

Electron wavelength: ~10 nm or less

Diameter of Carbon Nanotube 3

Diameter of DNA spiral 2

Diameter of C60 Buckyball 0.7

Diameter of Benzene ring 0.28

Size of one Atom~0.1

• Consider a human hand

How Big is a Nanometer?

white blood cell

skin

DNA atomsnanoscale

Source: http://www.materialsworld.net/nclt/docs/Introduction%20to%20Nano%201-18-05.pdf

History of Nanomaterials• 1974 The word Nanotechnology first coined by Nario

Taniguchi, Univ. of Tokyo --- production technology to get ultra fine accuracy and precision – 1nm

• 1981 IBM invented STM scanning tunneling microscope which can move single atoms around

• 1985 new form of carbon discovered --- C60 buckminister fullerene 60 carbon atoms arranged in a sphere made of 12 pentagons and 20 hexagons

Lycurgus chalice 4th Century A.D. Appears green in reflected light and red if light is directed through it (70 nm particles of silver and gold in the glass)

Lycrugus cup with diffused light

Lycrugus cup with focused light

History of Nanomaterials

• 1991 carbon nanotubes discovered “graphitic carbon needles ranging from 4 nm – 30 nm and up to 1 micron in length”

( Sumino Iijima)

• 1993 First high quality quantum dots prepared --- very small particles with controlled diameters of CdS, CdSe, CdTe


• 2000 First DNA motor made similar to motorized tweezers may make computers 1000 more powerful.

Nature 406 (6796) 2000, 605-608.

DNA motors can be attached to electrically conducting molecules – act as basic switches


• 2001 prototype fuel cell made with nanotubes

• 2002 Nanomaterials make stain repellant trousers Nano-care khakis have nanowhiskers (10-100 nm in length)


• Nano airborne particles (100 -1000 nm) cause water to condense and form raindrops or snowflakes

• Plankton – varies in sizes from (1- 100 nm) Marine bacteria and viruses

Lesson from Nature

Glucose and Glucose oxidase

All cells require glucose (0.6 nm) as a fuel for metabolism.

Energy is released from glucose when it is precisely positioned relative to the glucose oxidase enzyme( 5 nm)

Lock and key mechanism common in biology

Actin and Myosin

Actin and myosin molecules form the system responsible for muscle contraction. The system operates by a series of steps where the head of myosin molecule pulls the actin past itself by 10–28 nm each step.

NATURE - Gecko Power

Gecko foot hairs typically have diametersof 200 – 500 nm. Weak chemical interaction between each hair and surface (each foot has over 1 million of these hairs) provides a force of10 N/cm2.

This allows Gecko’s to walk upside down across glass ceilings.

Bucky Balls (C60) were discovered in soot!

Nanoparticles in Smoke from Fires

FerrofluidsCoated Iron oxide nanoparticles

(wikipedia)

•Great demo•Buy ferrofluid, use •Synthesize ferrofluid

http://en.wikipedia.org/wiki/Image:Ferrofluid_Magnet_under_glass_edit.jpg

Nanoscience Is Everywhere in Nature

• Living cells have been using their own nanoscale devices to create structures one atom or molecule at a time for millions of years.

• To be specific, DNA is copied, proteins are formed, and complex hormones are manufactured by cellular devices far more complex than the most advanced manufacturing processes we have today.

http://dallas.bizjournals.com/dallas/stories/2001/09/10/focus2.html?page=3

http://dallas.bizjournals.com/dallas/stories/2001/09/10/focus2.html?page=3

So How Did We Get Here?

New Tools!As tools change, what we can

see and do changes

Light microscope(magnification up to 1000x)

to see red blood cells (400x)

Sources: http://www.cambridge.edu.au/education/PracticeITBook2/Microscope.jpghttp://news.bbc.co.uk/olmedia/760000/images/_764022_red_blood_cells300.jpg

Using Light to See

• The naked eye can see to about 20 microns• A human hair is about 50-100 microns thick

• Light microscopes let us see to about 1 micron• Bounce light off of surfaces to create images

Greater resolution to see things like blood cells in greater detail

(4000x)

Sources: http://www.biotech.iastate.edu/facilities/BMF/images/SEMFaye1.jpghttp://cgee.hamline.edu/see/questions/dp_cycles/cycles_bloodcells_bw.jpg

Using Electrons to See

• Scanning electron microscopes (SEMs), invented in the 1930s, let us see objects as small as 10 nanometers– Bounce electrons off of surfaces to create images– Higher resolution due to small size of electrons

About 25 nanometers

This is about how big atoms are compared with the tip of the microscope

Source: Scientific American, Sept. 2001

Touching the Surface

• Scanning probe microscopes, developed in the 1980s, give us a new way to “see” at the nanoscale

• We can now see really smallthings, like atoms, and move them too!

Scanning Probe Microscopes

• Atomic Force Microscope (AFM)– A tiny tip moves up and down in response to the

electromagnetic forces between the atoms of the surface and the tip

– The motion is recorded and used to create an image of the atomic surface

• Scanning Tunneling Microscope (STM)– A flow of electrical current occurs between the tip and

the surface– The strength of this current is used to create an image of

the atomic surface

Source: http://www.uwgb.edu/dutchs/GRAPHIC0/GEOMORPH/SurfaceVol0.gif

Is Gold Always “Gold”?

• Cutting down a cube of gold– If you have a cube of pure gold

and cut it, what color would the pieces be?

– Now you cut those pieces. What color will each of the pieces be?

– If you keep doing this - cutting each block in half - will the pieces of gold always look “gold”?

Source: http://www.nano.uts.edu.au/pics/au_atoms.jpg

Nanogold

• Well… strange things happen at the small scale– If you keep cutting until the gold

pieces are in the nanoscale range, they don’t look gold anymore… They look RED!

– In fact, depending on size, they can turn red, blue, yellow, and other colors

• Why?– Different thicknesses of

materials reflect and absorb light differently

12 nm gold particles look red

Other sizes are other colors

Nanostructures

What kind of nanostructures can we make?

What kind of nanostructures exist in nature?

Source: http://www.library.utoronto.ca/engineering-computer-science/news_bulletin/images/nanotube.jpeg

Model of a carbon nanotube

Carbon Nanotubes

• Using new techniques, we’ve created amazing structures like carbon nanotubes• 100 time stronger than

steel and very flexible• If added to materials

like car bumpers, increases strength and flexibility

Model of Buckminsterfullerene

Source: http://digilander.libero.it/geodesic/buckyball-2Layer1.jpg

Carbon Buckyballs (C60)

• Incredible strength due to their bond structure and “soccer ball” shape

• Could be useful “shells” for drug delivery • Can penetrate cell walls • Are nonreactive (move

safely through blood stream)

Source: http://faculty.abe.ufl.edu/~chyn/age2062/lect/lect_06/lect_06.htm http://www.zephyr.dti.ne.jp/~john8tam/main/Library/influenza_site/influenza_virus.jpg

Biological Nanomachines in Nature

• Life begins at the nanoscale– Ion pumps move

potassium ions into and sodium ions out of a cell

– Ribosomes translate RNA sequences into proteins

– Viruses infect cells in biological organisms and reproduce in the host cell

Influenza virus

Building Nanostructures

How do you build things that are so small?

Fabrication Methods

• Atom-by-atom assembly– Like bricklaying, move atoms into place one

at a time using tools like the AFM and STM• Chisel away atoms

– Like a sculptor, chisel out material from a surface until the desired structure emerges

• Self assembly– Set up an environment so atoms assemble

automatically. Nature uses self assembly (e.g., cell membranes)

IBM logo assembled from individual xenon atoms

Polystyrene spheres self-assembling

Source: http://www.phys.uri.edu/~sps/STM/stm10.jpg; http://www.nanoptek.com/digitalptm.html

Example: Self Assembly By Crystal Growth

• Grow nanotubes like trees– Put iron nanopowder crystals

on a silicon surface– Put in a chamber– Add natural gas with carbon

(vapor deposition)– Carbon reacts with iron and

forms a precipitate of carbon that grows up and out

Growing a forest of nanotubes!

• Because of the large number of structures you can create quickly, self-assembly is the most important fabrication technique

Source: http://www.chemistry.nmsu.edu/~etrnsfer/nanowires/

Arrested Precipitation: General Approach

• Aqueous reduction of metal salts (Ag, Au) in the presence of• citrate ions• – Chemisorption of organic ligands for handling• – Distribution varies > 10%

II-VI ME nanocrystals (NCs) (M =Zn, Cd, Hg; X = S, Se, Te)• – Metal alkyls + organophosphinechalcogenides• – Phosphine binding to Mcontrolled by temperature• – Ostwald ripening allows for size-selective aliquots; growth time for1-2 nm NCs in minutes

Synthesis of Nanomaterials

• CdSe nanocrystals

• CdO + oleic acid + octadecene• Heat to 250° C to dissolve the CdO

• Selenium + octadecene + tributylphosphine• Heat to 150° C to dissolve the selenium

• Transfer Se solution to the Cd solution• Take aliquots

47

• Materials– Stain-resistant clothes

• Health Care– Chemical and biological

sensors, drugs and delivery devices

Potential Impacts of Nanotechnology

Thin layers of gold are used in tiny medical devices

Carbon nanotubes can be used for H fuel storage

Possible entry point for nanomedical device

• Technology– Better data storage

and computation• Environment

– Clean energy, clean air

48

Materials: Stain Resistant Clothes

• Nanofibers create cushion of air around fabric– 10 nm carbon whiskers bond with cotton – Acts like peach fuzz; many liquids roll off

Sources: http://www.sciencentral.com/articles/view.php3?article_id=218391840&cat=3_5http://mrsec.wisc.edu/Edetc/IPSE/educators/activities/nanoTex.html

Nano pants that refuse to stain;Liquids bead up and roll off

Nano-Care fabrics with water, cranberry juice, vegetable oil, and mustard after 30 minutes (left)

and wiped off with wet paper towel (right)

49

Materials: Paint That Doesn’t Chip

• Protective nanopaint for cars– Water and dirt

repellent– Resistant to chipping

and scratches– Brighter colors,

enhanced gloss– In the future, could

change color and self-repair?

Mercedes covered with tougher, shinier nanopaint

Sources: http://www.supanet.com/motoring/testdrives/news/40923/

50

Environment: Paint That Cleans Air

• Nanopaint on buildings could reduce pollution– When exposed to

ultraviolet light, titanium dioxide (TiO2) nanoparticles in paint break down organic and inorganic pollutants that wash off in the rain

– Decompose air pollution particles like formaldehyde

Buildings as air purifiers?

Sources: http://english.eastday.com/eastday/englishedition/metro/userobject1ai710823.html

51

Environment: Nano Solar Cells

• Nano solar cells mixed in plastic could be painted on buses, roofs, clothing – Solar becomes a cheap energy alternative!

Source: http://www.berkeley.edu/news/media/releases/2002/03/28_solar.html

Nano solar cell: Inorganic nanorods embedded in semiconducting polymer, sandwiched between two electrodes

] 200 nm

52

Technology: A DVD That Could Hold a Million Movies

• Current CD and DVD media have storage scale in micrometers

• New nanomedia (made when gold self-assembles into strips on silicon) has a storage scale in nanometers– That is 1,000 times more storage

along each dimension (length, width)…

Source: Images adapted from http://uw.physics.wisc.edu/~himpsel/nano.html

…or 1,000,000 times greater storage density in total!

53

Technology: Building Smaller Devices and Chips

• Nanolithography to create tiny patterns– Lay down “ink” atom by atom

Mona Lisa, 8 microns tall, created by AFM nanolithography

Sources: http://www.ntmdt.ru/SPM-Techniques/Principles/Lithographies/AFM_Oxidation_Lithography_mode37.htmlhttp://www.chem.northwestern.edu/~mkngrp/dpn.htm

Transporting molecules to a surface by dip-pen nanolithography

54

Health Care: Nerve Tissue Talking to Computers

• Neuro-electronic networks interface nerve cells with semiconductors– Possible applications in brain research,

neurocomputation, prosthetics, biosensors

Snail neuron grown on a chip that records the neuron’s activity

Source: http://www.biochem.mpg.de/mnphys/publications/05voefro/abstract.html

55

Health Care: Detecting Diseases Earlier

• Quantum dots glow in UV light– Injected in mice, collect in tumors– Could locate as few as 10 to 100 cancer cells

Sources: http://vortex.tn.tudelft.nl/grkouwen/qdotsite.htmlhttp://www.whitaker.org/news/nie2.html

Early tumor detection, studied in mice

Quantum Dots: Nanometer-sized crystals that contain free electrons and emit photons when

submitted to UV light

56

Health Care: Growing Tissue to Repair Hearts

• Nanofibers help heart muscle grow in the lab– Filaments ‘instruct’ muscle to grow in orderly way– Before that, fibers grew in random directions

Source: http://www.washington.edu/admin/finmgmt/annrpt/mcdevitt.htm

Cardiac tissue grown with the help of nanofiber filaments

57

Health Care: Preventing Viruses from Infecting Us

• Nanocoatings over proteins on viruses– Could stop viruses from binding to cells– Never get another cold or flu?

Sources: http://www.zephyr.dti.ne.jp/~john8tam/main/Library/influenza_site/influenza_virus.jpghttp://pubs.acs.org/cen/topstory/8005/8005notw2.html

Influenza virus: Note proteins on outside that bind to cells

Gold tethered to the protein shell of a virus

58

Health Care: Making Repairs to the Body

• Nanorobots are imaginary, but nanosized delivery systems could…– Break apart kidney stones, clear plaque from

blood vessels, ferry drugs to tumor cells

Source: http://www.genomenewsnetwork.org/articles/2004/08/19/nanorobots.php

FNI 1A 59

The Nano Industry

• Equipment suppliers– Imago Instruments – Atom probe

microscope– Hysitron Inc– Thermo electron

• Advanced materials– 3M– Cima Nanotech

• Electronics – A natural progression– Intel– HP– Motorola– IBM

• Biotechnology– Platypus– Bioforce Nanoscience– Ace Ethanol

• Healthcare– Medtronic– Boston Scientific

• Energy– Nanodynamics – Fuel cells– Konarka – Flexible solar panels– Cymbet

• Defense and security– Detecting explosives and bio

agents– MIT Institute of Soldier

Nanotechnologies

FNI 1A 60

• NNI http://www.nano.gov/ • NNIN http://www.nnin.org/ • MRSEC http://www.mrsec.wisc.edu/Edetc/ • NanoHUB http://www.nanohub.org/ • Conferences: NSTI, UMN,

– http://www.nsti.org/ – http://www.nano.umn.edu/conference2008/

• Nanorite Center http://www.nanorite.org/ • Nano in the News

The Nano Industry

http://www.nano.gov/

http://www.nnin.org/

http://www.mrsec.wisc.edu/Edetc/

http://www.nanohub.org/

http://www.nsti.org/

http://www.nano.umn.edu/conference2008/

http://www.nanorite.org/

FNI 1A 61

Future of Nanotechnology“Nanotechnology products worldwide will be $2.6 Trillion or 15% of global manufacturing output.” Investing in Nanotechnology -- Jack Uldrich

Enablers and tools: Hysitron, Imago

Nanomaterials: Carbon Nanotechnologies, Aspen Aerogels

Fortune 500 Companies: 3M, Affymetrix, Cabot, Dow, Dupont, Kodak, Texaco, AMD, GE, HP, IBM, Intel, Motorola, NEC

Disrupters: Bioforce Nanoscience, Nanosolar

62

Potential Risks of Nanotechnology

• Health issues– Nanoparticles could be inhaled, swallowed, absorbed

through skin, or deliberately injected– Could they trigger inflammation and weaken the

immune system? Could they interfere with regulatory mechanisms of enzymes and proteins?

• Environmental issues– Nanoparticles could accumulate in soil, water, plants;

traditional filters are too big to catch them• New risk assessment methods are needed

– National and international agencies are beginning to study the risk; results will lead to new regulations

63

Summary: Science at the Nanoscale

• An emerging, interdisciplinary science– Integrates chemistry, physics, biology, materials

engineering, earth science, and computer science• The power to collect data and manipulate particles at

such a tiny scale will lead to– New areas of research and technology design – Better understanding of matter and interactions– New ways to tackle important problems in healthcare,

energy, the environment, and technology– A few practical applications now, but most are years or

decades away

Mother Nature

Mankind has always found inspiration in Mother Nature. Today developingtechnologies allow us to probe and better understand the nanoscience of Mother Nature.

FNI 1A 65

1. Intro to NanoNano Industry Ch 1, 2,16

2. The Nano DebateSmalley vs Drexler Ch 15

3. History of NanoFuture of Nano Ch 15

4. Scale of Things Nano Ch 1

5. NanochemistryCh 3

6. The Atom GameCh 3

7. Quantum mechanics (Ch 6) Unit 1Test

8. Waves – Slinkys, Light and Orbitals Ch 3

9. Tools of Nano Ch 3 10. Microscopy 1 Optical and Electron Ch 3

11. Electron microscopy Ch 3

12. Microscopy 2 Electron beam specimen interactions

13. Scanning probe microscopy Ch 3

14. Microscopy 3 Scanning Probe Ch 3

15. Other Tools Ch 3Test 2

16. UWEC Field Trip

17. X-Ray Analysis Ch 3

18. X-Ray Diffraction 19. Carbon Nanotubes Ch 4

22. Carbon Nanotubes

21. Nanomaterials Ch 5, 12

20. Gold Nanoparticles

23. Synthesis/self assembly/Test 3

24. Magnetic Nanoparticles

25. Special Topics Energy Ch 9

26. Alternative energy applications of Nano

27. Special TopicsBiomedical Ch 10-11

28. Lab on a Chip

29. Student Presentations

30. Student Presentations

31. Final Exam 32. Last Day

Introduction to Nanoscience

introduction to nanoscience and nanotechnology

Education

carbon atoms

nm causewater

nm particles of silver

electron wavelength

electrons wavelength

small particles

small scale

new form of carbon