1. Nanotechnology Basics (HS) David T. Shaw State University of New York at Buffalo

2. What is Nanotechnology? WHAT DOES NANOTECHNOLOGY MEAN TO YOU?

3. The study of objects and phenomena at a very small scale, roughly 1 to 100 nanometers (nm) – 10 hydrogen atoms lined up measure about 1 nm – A grain of sand is 1 million nm, or 1 millimeter, wide What’s interesting about the nanoscale? – Nanosized particles exhibit different properties than larger particles of the same substance Studying phenomena at this scale will… – Change our understanding of matter – Lead to new questions and answers in many areas, like health care, energy, technology What is Nanotecnology? 3

4. How Small is Nanometer? 1 nm = 10 -9 meter

5. How Small is Nanometer?

6. What’s So Special About Nano? Using new scientific tools, we have found that nano- sized particles of a given substance exhibit different properties than larger particles of the same substance As we study these materials at the nanoscale, we are –Learning more about the nature of matter –Developing new theories –Learning how to manipulate their properties to develop new products and technologies

7. Painting On Solar Cells Nano solar cells mixed in plastic could be painted on buses, roofs, clothing –Solar becomes a cheap energy alternative! http://www.berkeley.edu/news/media/releases/2002/03/28_solar.html Inorganic nanorods embedded in semiconducting polymer -- sandwiched between two electrodes

8. History of Nanotechnology Some have argued that nanoscience started billions year ago, when the first living cells emerge. Cells house nanoscale biomachines perform such tasks as manipulating genetic materials and supplying energy. Dunin-Borkowski Science (98) Natural chains of magnetic nano-crystals in bacteria

9. “There’s Plenty of Room at the Bottom” Most, however, consider Richard Feynman’s famed talk in1959 as a historical moment for nanoscale science and technology The accuracy of Feynman’s vision is breath- taking. A few of his predictions include: electron and ion beam fabrication, molecular beam epitaxy, nanoimprint lithography, scanning tunneling microscopy, single electron transistors, spin electronics, and nanoelectromechanical systems (NEMS). To read the entire Feynman’s classic paper, please ClickClick

10. Genesis of Nanotechnology 00 Chemistry 96 Chemistry 86 Physics 56 Physics 97 chemistry (Mitre 96)

11. New Tools As tools change, what we can see and do changes

12. Light microscope (magnification up to 1000x) to see red blood cells (400x) Sources: http://www.cambridge.edu.au/education/PracticeITBook2/Microscope.jpg http://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

13. Greater resolution to see things like blood cells in greater detail (4000x) Sources: http://www.biotech.iastate.edu/facilities/BMF/images/SEMFaye1.jpg http://cgee.hamline.edu/see/questions/dp_cycles/cycles_bloodcells_bw.jpg Using Electrons to See Scanning electron microscopes, invented in the 1930s, let us see down to about 10 nanometers Bounce electrons off of surfaces to create images Higher resolution due to small size of electrons

14. Touching the Surface Scanning probe microscopes, develop- ed in the 1980s, give us a new way to “see” at the nanoscale We can now see really small things, like atoms, and move them too! This is about how big atoms are compared with the tip of the microscope Source: Scientific American, Sept. 2001

15. Tools of Nanotechnology Bright spots  electrons, dark spots  holes. Images of movement of electrons and holes through a semi-conductor substrate Yoo et al, Science (97) Development of STM-related techniques greatly accelerates the progress of nanotechnology

16. STM Art Gallery IBM coronene Omicron Li, PRL(02)

17. How Do Properties of Nanostructures Change? Properties of a substance depend on: –Size of the aggregation of particles –Surface to volume ratio Also, at the nanoscale, some properties such as boiling temperature do not apply –Vapor pressure becomes less and less meaningful when you have smaller and smaller numbers of particles –When you have 50 molecules there are no bubbles!

18. Sources: http://www.bc.pitt.edu/prism/prism-logo.gif http://www.physics.umd.edu/lecdem/outreach/QOTW/pics/k3-06.gif Size-Dependent Properties Properties of a material –Describe how the material acts under certain conditions –Are often measured by looking at large (~10 23 ) aggregation of atoms or molecules Types of properties –Optical (e.g. color, transparency) –Electrical (e.g. conductivity) –Physical (e.g. hardness, boiling point) –Chemical (e.g. reactivity, reaction rates)

19. Optical Properties Example: Gold Bulk gold appears yellow in color Nanosized gold appears red in color –The particles are so small that electrons are not free to move about as in bulk gold –Because this movement is restricted, the particles react differently with light Sources: http://www.sharps-jewellers.co.uk/rings/images/bien-hccncsq5.jpg http://www.foresight.org/Conferences/MNT7/Abstracts/Levi/ 12 nanometer gold particles look red “Bulk” gold looks yellow

20. Why Do Properties Change? Four important ways in which nanoscale materials may differ from macro scale materials –Gravitational forces become negligible and electromagnetic forces begin to dominate –Quantum mechanics is used to describe motion and energy instead of classical mechanics –Greater surface to volume ratios –Random molecular motion becomes more important

21. Dominance of Electromagnetic Forces Because the mass of nanoscale objects is so small, gravity becomes negligible –Gravitational force is a function of mass and is weak between nanosized particles –Electromagnetic force is not affected by mass, so it can be very strong even when we have nanosized particles –The electromagnetic force is much more stronger than gravitational force at nanoscale

22. Quantum Mechanical Model Needed Classical mechanical models explain phenomena well at the macro scale level, but break down at the nano- scale level Four phenomena that quantum mechanical models can explain (but classical mechanical models cannot) –Discreteness of energy –The wave-particle duality of light and matter –Quantum tunneling –Uncertainty of measurement

23. Surface to Volume Ratio Increases As surface to volume ratio increases –A greater amount of a substance comes in contact with surround- ing material –This results in better catalysts, since a greater proportion of the material is exposed for potential reaction Source: http://www.uwgb.edu/dutchs/GRAPHIC0/GEOMORPH/SurfaceVol0.gif

24. Source: http://galileo.phys.virginia.edu/classes/109N/ more_stuff/Applets/brownian/brownian.html Random Molecular Motion is Significant Random motion at the macro scale –Small compared the size of the substance –We can barely detect motion of dust particles on the surface of water Random motion at the the nanoscale –Large when compared to the size of the substance –The molecules that make up the dust particle are moving wildlydust particle

25. How might new innovations change our lives? –Materials: stain-resistant clothing –Environment: clean energy, clean air –Technology: better data storage and computation –Heathcare: chemical and biological sensors, drugs and delivery devices Potential Impact of Nanotechnology Thin layers of gold are used in tiny medical devices Carbon nanotubes can do many things! Possible entry point for nanomedical device

26. A DVD That Could Hold a Million Movies New nanomedia could result in a million times greater storage density New nanomedia: Gold self- assembles into strips on silicon (scale is nanometers) Current CD and DVD media (scale is microns) Source: http://uw.physics.wisc.edu/~himpsel/nano.html

27. 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 Re: http://www.ntmdt.ru/SPM-Techniques/Principles/Lithographies/AFM_Oxidation_Lithography_mode37.html http://www.chem.northwestern.edu/~mkngrp/dpn.htm Transporting molecules to a surface by dip-pen nanolithography

28. 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

29. Detecting Diseases Earlier Cancer in Color

30. Growing Tissue to Repair Hearts Growing cardiac muscle tissue is an area of current research –Grown in the lab now, but the fibers grow in random directions –With the help of nanofiber filaments, it grows in an orderly way Could be used to replace worn out or damaged heart tissue Source: http://www.washington.edu/admin/finmgmt/annrpt/mcdevitt.htm Cardiac tissue grown with the help of nanofiber filaments

31. Sources: http://www.zephyr.dti.ne.jp/~john8tam/main/Library/influenza_site/influenza_virus.jpg http://pubs.acs.org/cen/topstory/8005/8005notw2.html Influenza virus: Note proteins on outside that bind to cells Preventing Viruses from Infecting Us The proteins on viruses bind to our body cells Could cover these proteins with nanocoatings –Stop them from recognizing and binding to our cells –We would never get the flu! A protein recognition system has been developed Gold tethered to the protein shell of a virus

32. Making Repairs to the Body Nanorobots are decades away, but 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

33. Summary An emerging, interdisciplinary Science and technology nano- scale, integrating chemistry, physics, biology, and earth science with technology The power to collect data and manipulate particles at nanoscale 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, environment, and technology –A few practical applications now, but most are years or decades away