1. Self Assembly Nanoscience Education Institute

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

3. 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.... First a case you already know: The nanofilm Franklin made this observation, but did not determine the thickness.

4. The first person to make worthwhile, reproducible measurements on monolayers was Agnes Pockels who lived in Braunschweig, Germany. Agnes Pockels was the original housewife superstar. She performed her first experiments on monolayers in her kitchen in her home, starting in about 1882. She used a tin tray as the water container and a small disk suspended from a balance with a slide weight to measure the surface tension of the water. By contaminating the water surfaces with different materials, Pockels created monolayers and observed their properties when confining the water surfaces to various areas using waxed tin strips. Pockels observed that the surface tension of a water surface varies with its size and depends on the type of contamination. She sent an account of her work to Lord Rayleigh, who recommended its publication in the journal Nature. Lord Rayleigh had a similar interest in the science of interfaces and was inspired by Pockels to make his own experiments, from which he concluded that these layers were just a single molecule thick. Agnes Pockels

5. Langmuir-Blodgett Film pressure e.g., steric acid monolayer film water hydrophilic end hydrophobic end of an amphiphilic molecule

6. The people behind the research Irving LangmuirKatharine Burr Blodgett Nobel prize in chemistry for his work in surface chemistry First woman to earn a PhD in Physics from Cambridge University Performed their research at General Electric in Schenectady, New York

7. Langmuir-Blodgett Film Transferred to a Solid Surface Must control movable barrier to keep constant pressure multiple dips - multiple layers solid liquid

8. What drives and governs self assembly? As you view the following images you should consider the question:

9. Tobacco Mosaic Virus wisc.edu nih.gov

10. Diatoms priweb.org sinancanan.net

11. Abalone

12. The Cell and Its Hierarchy ebi.ac.uk

13. Gecko feet

14. Publicity: http://www.sciencedaily.com/releases/2012/01/120125101950.htm Scorpion Armor Original article: http://dx.doi.org/10.1021/la203942r The scorpion a special grooved shield to protect itself against scratches from desert sand. Researchers study this to help develop materials with good erosion resistance for helicopters, pipes, and other applications.

15. Ultra-tough Shrimp Hammer The peacock mantis shrimp feasts on snails, crabs and other mollusks and crustaceans by smashing through their shells with its front hammer-like claws, delivering 500 Newtons of force. This is powerful enough to punch through aquarium glass. Science magazine June 8, 2012 DOI: 10.1126/science.1218764

16. Whitesides et al. Science 295, 2418 (2002); Self assembly at all scales?

20. What enables self assembly? Static assembly (thermodynamic free energy minimum; requires agitation) -- once formed it is stable Dynamic assembly (kinetically formed, not necessarily thermodynamic minimum) -- not necessarily stable Forces of chemical bonding (4) covalent, ionic, van derWaals, hydrogen Other forces (magnetic, electrostatic, fluidic,...) Polar/Nonpolar (hydrophobicity) Shape (configurational) Templates (guided self assembly) Kinetic conditions (e.g., diffusion limited)

21. SAM: Self Assembled Monolayer Chemisorbed molecules Stabilized by intermolecular van der Waals interaction solid molecules from solution

22. SAM: Self Assembled Monolayer Review article: J.C. Love, et al., Chem. Rev. 2005, 105, 1103 (G. Whitesides group, Chem Dept, Harvard) HS(CH 2 ) n X alkanethiol on gold (Au) where X is the end group of the chain –CH 3, –OH, or –COOH Longer alkanethiol molecules have greater thermodynamic stability

23. SAMs on Nanoparticles J.C. Love, et al., Chem. Rev. 2005, 105, 1103 gold NP There are now many configurations and uses of SAMs imperfect packing

24. Nanoparticle Monolayer Formed at a Liquid-Air Interface

25. Nanoparticle Monolayer Formation Nature Materials MOVIE toluene Requirements: rapid evaporation excess dodecane present attractive interation to liq- air interface and between particles

26. SELF ASSEMBLY with DIBLOCK COPOLYMERS Block “ A ” Block “ B ” 10% A 30% A 50% A 70% A 90% A ~10 nm Ordered Phases PMMA PS Scale set by molecular size

27. CORE CONCEPT FOR NANOFABRICATION Deposition Template Etching Mask Nanoporous Membrane Remove polymer block within cylinders (expose and develop) Versatile, self-assembling, nanoscale lithographic system (physical or electrochemical)

28. Array Period = 24 nm Pore Diameter = 14 nm MW = 42,000 PS/PMMA TEMPLATE CHARACTERIZATION 100 cpp SEM SAXS

29. Improving Order: Guided Assembly in a Trench: Graphioepitaxy UMass-Seagate assemble here side view top view

30. nanoporous template Nanomagnets in a Self-Assembled Polymer Mask 1x10 12 magnets/in 2 Data Storage......and More

31. Metal Nanorings Ferromagnetic cobalt rings as small as 15 nm OD

32. Mohan Srinivasarao, et al. Science 292, 79 (2001). Kinetic Self-Assembly - by Breath Figures Polystyrene Film

33. More Fabrication by Breath Figures UMass: Alexander Böker, Yao Lin, Kristen Chiapperini, Reina Horowitz, Mike Thompson, Vincent Carreon, Ting Xu, Clarissa Abetz, Habib Skaff, A. D. Dinsmore, Todd Emrick and Thomas P. Russell, Nature Materials 3, 302 - 306 (2004) a, Breath-figure pattern obtained with pure polystyrene. b, Optical and c, confocal fluorescence microscope images of different areas of a sample obtained from solvent-casting a polystyrene film from chloroform with CdSe nanoparticles. Scale bars: 16 mum. The inset in c shows a fluorescence intensity scan along the line indicated.

34. Anodized Aluminum Oxide Templates Aluminum Nanoporous aluminum oxide (AAO) ~ 40 V counter electrode Anodization Acid Bath I e.g., Keller, et al., J. Electrochem. Soc. 100, 411 (1953) Masuda & Fukuda, Science 268, 1466 (1995) (oxalic, sulfuric, or phosphoric acid) Masuda, et al.

35. Proposed AAO Growth Mechanism Figure adapted from Jessensky, Müller, & Gösele, Appl. Phys. Lett. 72, 1173 (1998) Al 2 O 3 E Al Al 3+ O 2- Density mismatch between Al and Al 2 O 3 Some Al 3+ goes to solution Mechanical stress yields pore growth in uniform hexagonal array Pore diameters of ~ 10-400 nm possible by choice of anodization conditions

36. Improving AAO Order at Surface SiC stamp Aluminum anodize e.g., Masuda et al., Appl. Phys. Lett 71, 2770 (1997); Choi, et al., J. Vac. Sci. Tech. B 21, 763 (2003)

37. Molecular Recognition ("lock and key" bonding) biotin-avidin pair (site-specific binding) thymine (T) adenine (A) guanine (G) cytosine (C) hydrogen bonding

38. Using Synthetic DNA for Designer Structures Ned Seeman, NYU Designer DNA molecules can be synthesized chemically, and allowed to assemble into a specific configuration of lowest energy.

39. Programmed DNA Folding to Make "DNA Origami" P.W.K. Rothemund, Nature 440, 297 (2006)

40. Programmed DNA Folding: Advanced Designs William Shih, Harvard University

41. Microfluidic Assembly Application: RFID Alien Technology Nanoscale Phase Separation IBM "air gap" technology Introducing nanoscale air pockets into the insulating material separating wires on a computer chip -- lowers the capacitance flow direction Parts, having unique shape, are delivered via fluid flow to mating pockets on an assembly substrate.

42. NEW! Self-Folding Objects https://www.youtube.com/watch?v= NKRWZG67dtQ http://www.prism- magazine.org/jan13/feature_01.cfm

43. Large Scale Self-Assembly (Geological) Giant's Causeway (Northern Ireland) Volcanic basalt cooled rapidly to form these (mostly) hexagonally shaped columns

44. Explore concepts of self assembly in the classroom Balls in a box (best packing) Straws or toothpicks in a container (lattice and defects) How shape influences packing density and the symmetry of assembled structures Objects floating on water (Cheerios and other shapes) Two-dimensional array of magnets; floating magnets - attractive and repulsive cases Crystallization - explore how conditions influence size and perfection of crystals Underlying principles: forces (non-directional or directional), shape, thermal agitation