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
"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)
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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)
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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)
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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.
"We're not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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
History of Nanomaterials
• 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
History of Nanomaterials
• 2001 prototype fuel cell made with nanotubes
• 2002 Nanomaterials make stain repellant trousers Nano-care khakis have nanowhiskers (10-100 nm in length)
History of Nanomaterials
• 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
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
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
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• 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
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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)
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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/
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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
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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
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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!
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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
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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
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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
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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
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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
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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
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
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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
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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