Nanotechnology

1. Nanotechnology What, How, Why? MAST, October 22, 2010

2. Brought to you by … • NSF grant DMI-0531171 to the UMass Amherst Center for Hierarchical Manufacturing • Mort Sternheim, Director, STEM Education Institute, mort@umassk12.net • Rob Snyder, STEM Ed, snyder@umassk12.net • www.umassk12.net/nano

3. Today’s Agenda • Introduction – Mort Sternheim • Make a nanofilm – Rob Snyder • Was Franklin the first nanotechnologist?

4. Nanotechnology Summer Institute • Monday to Friday, June 27-July 1, 2011 UMass Amherst • Middle and High School Science, Math, and Technology Teachers; Informal Educators (from anywhere) • $75/day stipends ($375 total), materials, parking, lunches • Housing (new air conditioned dorms) and meals for those outside the commuting radius • 3 graduate credits available at reduced cost; free PDP's (Professional Development Points) • Also available: STEM DIGITAL Institute July 12-16 • See flyer

5. What: Nanotechnology Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications. 1 nanometer = 1 billionth of a meter = 1 x 10-9 m nano.gov

6. Single Hair Width = 0.1 mm How small are nanostructures? = 100 micrometers = 100,000 nanometers !

7. DNA 6,000 nanometers Red blood cell 3 nanometers Smaller still Hair .

8. Relative sizes • Atomic nuclei ~ 10-15 meters = 10-6 nanometers • Atoms ~ 10-10 meters = 0.1 nanometers • Nanoscale ~ 1 to 100 nanometers ~ 10 to 1000 atoms • Everyday world ~ 1 meter = 109 nanometers • More on powers of ten on our website, others

9. How: Making Nanostructures

10. Lithography • Deposition • Etching • Machining • Chemical • Self-Assembly Making Nanostructures: Nanomanufacturing "Top down" versus "bottom up" methods

11. Self Assembly

12. ~10 nm SELF ASSEMBLY with DIBLOCK COPOLYMERS Block “B” Block “A” PS PMMA Phase separation...on the nanoscale Ordered Phases 10% A 30% A 50% A 70% A 90% A

13. Deposition Template Etching Mask Nanoporous Membrane Self-Assembled Nanoscale "Stencils" (physical or electrochemical) Remove polymer block within cylinders (expose and develop) A self-assembling, nanoscale lithographic system

14. Why: Applications

15. Why do we want to make things at the nanoscale? • To make better and new products: smaller, cheaper, faster and more effective. (Electronics, catalysts, water purification, solar cells, coatings, medical diagnostics & therapy, etc) • To introduce completely new physical phenomena to science, technology. (Quantum behavior and other effects.)

16. http://www.masspolicy.org/pdf/workshop/rejeski.pdf

17. 20 GB 40 GB 10 GB 2001 2002 2004 Hard drive Magnetic data storage 80 GB 160 GB 2006 2007 Example: Data storage capacity of the iPod Uses nanotechnology! Nanomagnets!

18. Scaling Down to the Nanoscale Increases the amount of data stored on a fixed amount of “real estate” ! Now ~ 100 billion bits/in2, future target more than 1 trillion bits/in2 25 DVDs on a disk the size of a quarter, or all Library of Congress books on a 1 sq ft tile!

19. Solar Cells Benefit: Sun is an unlimited source of electronic energy. Konarka

20. “load” Nanostructured Solar Cells Sunlight - Voltage + Current More interface area - More power!

21. Targeted Cancer Therapy

22. Cancer Therapy targeted therapy: hyperthermic treatment Nanoshells are coated with a substance that binds them to cancer cells. Absorb IR and destroy cancer cells with heat; no harm to healthy cells tumor gold nanoshells Naomi Halas group, Rice Univ. www.sciencentral.com/articles/view.php3?article_id=218392390

23. More Applications • Sunscreens with nanoparticles to block UVA • Earlier sunscreens only block UVB; UVA and UVB both cause cancer • Water purification with nanofilters • http://nanosense.org/ - sunscreen and nanofilters • Stain resistant fabrics • Better Kelvar bullet proof vests

24. Nanotechnology R&D is interdisciplinary and impacts many applications • Electronics • Materials • Health/Biotech • Chemical • Environmental • Energy • Aerospace • Automotive • Security • Forest products • And others • Physics • Chemistry • Biology • Materials Science • Polymer Science • Electrical Engineering • Chemical Engineering • Mechanical Engineering • Medicine • And others

25. Nanoscale Thin Films

26. Today’s Agenda • Ben Franklin’s Observation • Interactions between Oleic Acid and Water • Create a thin film of oleic acid • Calculate the thickness of the thin film of oleic acid

27. Was Ben Franklin an Early Nanoscientist?

28. Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773) ...At length being at Clapham, where there is, on the Common, a large Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....

29. 2 cm3 T = 20,000,000 cm2 ~ 2 cm3 V = 1 teaspoonful A = 0.5 acre ~ 2,000 m2 ... the Oil tho' not more than a Tea Spoonful ... ... perhaps half an Acre CHALLENGE: How thick was the film of Ben Franklin’s oil? Volume = (Area)(Thickness) V = A T T = V/A T = 0.0000001 cm T = 1 x 10-7 cm T = 1 x 10-9 m T = 1 nanometer 20,000,000 cm2

30. It would be difficult to conduct a thin film experiment on the UMass Amherst campus pond.

31. A plastic tray can be used to experiment with thin films.However, you need to use much less than a teaspoon of oil.

32. You will form a thin film on the surface of water using a small amount of one of olive oil’s ingredients.

33. That ingredient is oleic acid. The polar end of oleic acid molecules are attracted to polar water molecules.

34. When you pour a very small amount of oleic acid onto the surface of water, the oleic acid molecules can “self-assemble” into a thin layer.

35. In a small drop of oleic acid there are billions of oleic acid molecules that will stand up like blades of grass on the surface of water.

36. The thin film of oleic acid forms a Langmuir Film. The thin film can be confined to a specific area with a barrier. You will use small particles as a confining barrier. hydrophobic end water hydrophilic end

37. Water is in each plastic tray. Make a very dilute solution of oleic acid in alcohol. Determine how many drops of a very dilute solution are in one cm3 of the very dilute solution. Evenly sprinkle a layer of baby powder across the surface of the water. Let one drop of the very dilute solution of oleic acid spread across the surface of the water. The alcohol solvent will dissolve in water leaving a thin film of oleic acid solute on the surface Measure the average diameter of the circular layer of oleic acid. Now its your turn to create a thin layer on the surface of water.

38. The following steps correspond to the sequence of calculations on your calculation worksheet. Step 1: The volume fraction = 1 / 25 Step 2: 0.04 cm3 Step 3: 0.04 cm3 / 25 = 0.0016 cm3 Step 4: A group determined that 40 drops of the second dilute solution = 1.0 cm3. Step 5: If a group determined that 40 drops of the second solution of oleic acid had a volume of 1.0 cm3; Then 0.0016 cm3 / 40 = 0.00004 cm3. A Sample Calculation of the volume of oleic acid in just one drop of the second dilute solution

39. Step 6: If a group estimated that average diameter their thin film of oleic acid was 14.50 cm, then the average radius is 7.25 cm. Step 7: Area = 3.14 x R2 For example: The area of that thin film was 165.05 cm2 Step 8: If Volume = Area x Depth; Then: Depth = Volume / Area and the thickness of the example group’s film would be 2.42 x 10-7 cm. Step 9: 2.42 x 10-7 cm = 2.42 x 10-9 m = 2.42 nanometers A sample calculation of the thickness of the oleic acid film

40. What might be some sources of error when calculating the thickness of a layer of oleic acid? How could the sources of error be minimized? What would be some challenges when using a tray the size of a dinner plate? A Few Questions

41. The Big Ideas in Self-Assembly • Structural components are mobile. • The goal is a low energy equilibrium state. • Ordered structures result from a less ordered system. • Assembly is a result of attractive or repulsive forces between the components. • An environment is selected to induce designed interaction. • Components retain physical identity through and after. • The process is reversible or adjustable. Whitesides & Boncheva (2002)

42. Nanotechnology Summer Institute • Monday to Friday, June 27-July 1, 2011 UMass Amherst • Middle and High School Science, Math, and Technology Teachers; Informal Educators (from anywhere) • $75/day stipends ($375 total), materials, parking, lunches • Housing (new air conditioned dorms) and meals for those outside the commuting radius • 3 graduate credits available at reduced cost; free PDP's (Professional Development Points) • Also available: STEM DIGITAL Institute July 12-16 • See flyer