Pandit Deendayal Petroleum University Introduction to Nanoscience and Nanotechnology Dr. Bharat Parekh School of Technology Pandit Deendayal Petroleum University Gandhinagar-382007 Gujarat, India
Plan of the Talk• Nanoscience-Definition• Background• Lesson from Nature• Building nano structures• Synthesis of nanomaterials (CdTe)• Applications in different field• Nano Industry• Summary
Introduction• 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.)
What is Nanoscience? When people talk about Nanoscience, many start by describing things• Physicists and Material Scientists point to things likenew nanocarbon materials:• They effuse about nanocarbon’s strength and electricalproperties Graphene Carbon Nanotube C60 Buckminster Fullerene "Were 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) "Were not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
And Chemists note THEY’VE synthesized molecules for over acentury <= 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 "Were 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 lights wavelength"Were not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
And microtechnology has been rolling along for half a century! Microelectronics = Integrated circuits, PCs, 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)"Were not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
Indeed, microtechnology has gotten smaller EVERY yearMOORES 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: ICs had only been invented 7 years before! (by Moore, his Fairchild/Intel colleagues, and Texas Instruments Jack Kilby) But his "law" has since been followed for forty five years: (Source: www.intel.com/technology/mooreslaw/index.htm) "Were 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 "Were 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 CHANGESOr when OUR BEHAVIOR MUST CHANGE to make those things"Were 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 MECHANICS A 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: "Were not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
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 Things Millimeters Microns NanometersBall of a ball point pen 0.5Thickness of paper 0.1 100Human hair 0.02 - 0.2 20 – 200Talcum Powder 40Fiberglass fibers 10Carbon fiber 5Human red blood cell 4–6E-coli bacterium 1Size of a modern transistor 0.25 250Size of Smallpox virus 0.2 – 0.3 200 – 300 Electron wavelength: ~10 nm or lessDiameter of Carbon Nanotube 3Diameter of DNA spiral 2Diameter of C60 Buckyball 0.7Diameter of Benzene ring 0.28Size of one Atom ~0.1 "Were not in Kansas Anymore!" - A Hands-on Introduction to Nanoscience
How Big is a Nanometer? • Consider a human hand skin white blood cell DNA atoms nanoscaleSource: 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
History of NanomaterialsLycurgus chalice 4th Century A.D.Appears green in reflected light and red if light is directedthrough it (70 nm particles of silver and gold in the glass) Lycrugus Lycrugus cup with cup with focused light diffused 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. DNA motors can be attached to electrically conducting molecules – act as basic switches Nature 406 (6796) 2000, 605-608.
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)
Lesson from Nature• 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
Glucose and Glucose oxidaseAll cells require glucose (0.6 nm)as a fuel for metabolism.Energy is released from glucosewhen it is precisely positionedrelative to the glucose oxidaseenzyme( 5 nm)Lock and key mechanismcommon in biology
Actin and MyosinActin and myosinmolecules form the systemresponsible for musclecontraction.The system operates by aseries of steps where thehead of myosin moleculepulls the actin past itself by10–28 nm each step.
NATURE - Gecko PowerGecko foot hairs typically have diametersof 200 – 500 nm. Weak chemical interactionbetween each hair and surface (each foot hasover 1 million of these hairs) provides a forceof10 N/cm2.This allows Gecko’s to walk upside down acrossglass ceilings.
Nanoparticles in Smoke from Fires Bucky Balls (C60) were discovered in soot!
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
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 to see red blood cells Light microscope (400x) (magnification up to 1000x)Sources: http://www.cambridge.edu.au/education/PracticeITBook2/Microscope.jpghttp://news.bbc.co.uk/olmedia/760000/images/_764022_red_blood_cells300.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 (4000x) Greater resolution to see things like blood cells in greater detailSources: http://www.biotech.iastate.edu/facilities/BMF/images/SEMFaye1.jpghttp://cgee.hamline.edu/see/questions/dp_cycles/cycles_bloodcells_bw.jpg
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 small About 25 nanometers things, like atoms, and move them too! This is about how big atoms are compared with the tip of the microscopeSource: Scientific American, Sept. 2001
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
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.uwgb.edu/dutchs/GRAPHIC0/GEOMORPH/SurfaceVol0.gif
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 12 nm gold particles look red can turn red, blue, yellow, and other colors Other sizes are other colors • Why? – Different thicknesses of materials reflect and absorb light differentlySource: http://www.nano.uts.edu.au/pics/au_atoms.jpg
NanostructuresWhat kind of nanostructures can we make?What kind of nanostructures exist in nature?
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 a carbon nanotubeSource: http://www.library.utoronto.ca/engineering-computer-science/news_bulletin/images/nanotube.jpeg
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) Model of BuckminsterfullereneSource: http://digilander.libero.it/geodesic/buckyball-2Layer1.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 cellSource: http://faculty.abe.ufl.edu/~chyn/age2062/lect/lect_06/lect_06.htm Influenza virushttp://www.zephyr.dti.ne.jp/~john8tam/main/Library/influenza_site/influenza_virus.jpg
Building NanostructuresHow 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 IBM logo assembled • Chisel away atoms from individual xenon 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) Polystyrene spheres self- assemblingSource: 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 Growing a forest of nanotubes! forms a precipitate of carbon that grows up and out • Because of the large number of structures you can create quickly, self-assembly is the most important fabrication techniqueSource: http://www.chemistry.nmsu.edu/~etrnsfer/nanowires/
• 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
• 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
Potential Impacts of Nanotechnology • Materials • Technology – Stain-resistant clothes – Better data storage • Health Care and computation – Chemical and biological • Environment sensors, drugs and – Clean energy, clean air delivery devicesThin layers of gold are used in Carbon nanotubes can be used Possible entry point for tiny medical devices 47 for H fuel storage nanomedical device
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 Nano pants that refuse to stain; Nano-Care fabrics with water, cranberry juice, Liquids bead up and roll off vegetable oil, and mustard after 30 minutes (left) and wiped off with wet paper towel (right) 48Sources: http://www.sciencentral.com/articles/view.php3?article_id=218391840&cat=3_5http://mrsec.wisc.edu/Edetc/IPSE/educators/activities/nanoTex.html
Materials: Paint That Doesn’t Chip • Protective nanopaint for cars – Water and dirt repellent – Resistant to chipping and scratches Mercedes covered with tougher, shinier – Brighter colors, nanopaint enhanced gloss – In the future, could change color and self- repair? 49Sources: http://www.supanet.com/motoring/testdrives/news/40923/
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 Buildings as air purifiers? wash off in the rain – Decompose air pollution particles like formaldehyde 50Sources: http://english.eastday.com/eastday/englishedition/metro/userobject1ai710823.html
Environment: Nano Solar Cells • Nano solar cells mixed in plastic could be painted on buses, roofs, clothing – Solar becomes a cheap energy alternative! ] 200 nm Nano solar cell: Inorganic nanorods embedded in semiconducting polymer, sandwiched between two electrodes 51Source: http://www.berkeley.edu/news/media/releases/2002/03/28_solar.html
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 …or 1,000,000 – That is 1,000 times more storage along each dimensiontimes greater (length, storage density width)… in total! 52Source: Images adapted from http://uw.physics.wisc.edu/~himpsel/nano.html
Technology: Building Smaller Devices and Chips • Nanolithography to create tiny patterns – Lay down “ink” atom by atom Transporting molecules to a surface by Mona Lisa, 8 microns tall, created by dip-pen nanolithography AFM nanolithography 53Sources: http://www.ntmdt.ru/SPM-Techniques/Principles/Lithographies/AFM_Oxidation_Lithography_mode37.htmlhttp://www.chem.northwestern.edu/~mkngrp/dpn.htm
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 54Source: http://www.biochem.mpg.de/mnphys/publications/05voefro/abstract.html
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 Quantum Dots: Nanometer-sized crystals that contain free electrons and emit photons when submitted to UV light Early tumor detection, 55Sources: http://vortex.tn.tudelft.nl/grkouwen/qdotsite.html studied in micehttp://www.whitaker.org/news/nie2.html
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 Cardiac tissue grown with the help of nanofiber filaments 56Source: http://www.washington.edu/admin/finmgmt/annrpt/mcdevitt.htm
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? Gold tethered to the Influenza virus: Note proteins on protein shell of a virus outside that bind to cells 57Sources: http://www.zephyr.dti.ne.jp/~john8tam/main/Library/influenza_site/influenza_virus.jpghttp://pubs.acs.org/cen/topstory/8005/8005notw2.html
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 58Source: http://www.genomenewsnetwork.org/articles/2004/08/19/nanorobots.php
The Nano Industry • Biotechnology – Platypus• Equipment suppliers – Bioforce Nanoscience – Imago Instruments – Atom probe – Ace Ethanol microscope – Hysitron Inc • Healthcare – Thermo electron – Medtronic – Boston Scientific• Advanced materials – 3M – Cima Nanotech • Energy – Nanodynamics – Fuel cells• Electronics – A natural – Konarka – Flexible solar panels progression – Cymbet – Intel – HP • Defense and security – Motorola – Detecting explosives and bio – IBM agents – MIT Institute of Soldier NanotechnologiesFNI 1A 59
The Nano Industry• 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 NewsFNI 1A 60
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, NanosolarFNI 1A 61
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 regulations62
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 away63
Mother NatureMankind has always found inspiration inMother Nature. Today developingtechnologies allow us to probe and better understand thenanoscience of Mother Nature.
Introduction to Nanoscience1. Intro to Nano 2. The Nano Debate 3. History of Nano 4. Scale of ThingsNano Industry Ch 1, Smalley vs Drexler Future of Nano Ch 15 Nano Ch 12,16 Ch 155. Nanochemistry 6. The Atom Game 7. Quantum 8. Waves – Slinkys,Ch 3 Ch 3 mechanics (Ch 6) Light and Orbitals Ch Unit 1Test 39. Tools of Nano Ch 3 10. Microscopy 1 11. Electron 12. Microscopy 2 Optical and Electron microscopy Ch 3 Electron beam Ch 3 specimen interactions13. Scanning probe 14. Microscopy 3 15. Other Tools Ch 3 16. UWEC Field Tripmicroscopy Ch 3 Scanning Probe Ch 3 Test 217. X-Ray Analysis 18. X-Ray Diffraction 19. Carbon 22. CarbonCh 3 Nanotubes Ch 4 Nanotubes21. Nanomaterials Ch 20. Gold 23. Synthesis/self 24. Magnetic5, 12 Nanoparticles assembly/Test 3 Nanoparticles25. Special Topics 26. Alternative energy 27. Special Topics 28. Lab on a ChipEnergy Ch 9 applications of Nano Biomedical Ch 10-1129. Student 30. Student 31. Final Exam 32. Last DayPresentations FNI 1A Presentations 65