1. Goals for Today: Syllabus Review
Continue “Fundamental Nanoscience” Discussion
Assignments

2. Nanoscale science and engineering
here refer to the fundamental understanding and resulting technological advances arising from the exploitation of new physical, chemical and biological properties of systems that are intermediate in size, between isolated atoms and molecules and bulk materials, where the transitional properties between the two limits can be controlled.
-Mike Roco (NSF) 2001

3. Nanotechnology Heirarchy
Bulk Chemistry/Materials
(Chemistry & Physics accomplish the self-assembly)
Manufacturing (e.g. Intel)
directed assembly
Nanomachines
Self Replicators (life?)
Increasing Complexity
(information, design)

4. Moore’s 1st Law Chip Feature Size (nm) Year 400 300 200 100
Entering the
Nanoscale
Chip Feature Size (nm)
Trouble Predicted
1990
1995
2000
2005
2010
2015
Year

7. Technology: Components are getting smaller and smaller.
Interconnections between components are getting smaller and smaller.

8. Nano-Scale Science What’s so special? Size matters.
Properties of materials depend on their size.
We don’t normally notice…

9. NanoScience Issues Physical (e.g. surface effect) Chemical (bonding)
Quantum Mechanical
Information/Design

10. Washington National Gallery
Example: Gold
Michigan Gold
0.5 mm Gold Crystal
From Nevada
The Space Window
Washington National Gallery

11. WHY?
Why does gold look like gold until the particles get to nanometer size, and then the properties change dramatically?

12. Physical Surface Area Effect? Number of surface atoms =
Gold
Number of surface atoms =
number of bulk atoms L
Estimate:
6·2·L2 = 4·L3 – 6·2·L2
L = 6 L L
N = L3 = 216

13. Chemistry
Example: Carbon
Graphite
Diamond

14. Chemical Bonding is Vital
Soft material
Lubricant
Opaque
Electrical conductor
Thermal conductor
Highly anisotropic
Hardest material
Abrasive
Transparent
Electrical insulator
Excellent thermal conductor
Optically isotropic

15. NanoCarbon
C60
Buckyballs
Nanotubes
Nanocones

16. Nanotechnology Examples:
Scanning Electron Microscopy image of an individual multiwalled carbon nanotube contacted by four electric leads for resistivity measurements. 09/article3/article3.html

17. A prototype of a carbon nanotube based display
(Samsung Display Technology, courtesy of Y. Choi).   
09/article3/article3.html

19. Quantum Mechanics Matter (electron) has wave properties
Waves are related to probability of where to find particle
In bound systems, particles have
discrete states (think of electron orbitals in atoms)
Energy and other properties are quantized
(think of energy levels in atoms)

20. Quantum Dot (Barrier Potential)
Quantum dot pillars
in semiconductor.
L. P. Kouwenhoven
“artificial atoms”

21. States, Energies, Transitions
Allowed energy changes are quantized.

22. Quantum Applets

23. Double Barrier (Quantum Dots)
Energy
“Forbidden
Region”

24. Bringing Barriers Together…
Changes energy levels
(and device properties)
Changes electron states
Allows for tunneling
These changes can cause old technologies to fail.
Or:
You can capitalize on these properties for new devices.

25. Tunnelling
Passage of a particle from one “localized” area to another through a “forbidden” region.
Application:
Scanning Tunneling Microscopy
Potential Problems:
Electrons can “leak” to where they are not supposed to be.

26. Quantum Dot Tunneling?
Electric Force Microscope images of Ge quantum dots on Si-on-insulator.
Charge was deposited on upper right mesa and migrated to the lower left mesa in about an hour. (Univ. Wisconsin) (

27. Assignment: Nano in the Home…
Nanotechnology: The application of nanostructures into useful nanoscale devices.

28. Assignment For Next Time
Read Ratter & Rattner
chapters 1 & 2
Look over the brochure Nanotechnology: Shaping the World Atom by Atom.
Answer questions on hand-out
1-2 pages
(use complete sentences,
good grammar, etc.)

29. Nano at Home Examples:
Special additive to clothing for non-stain and wrinkle-free
Nano-composite coating for tennis balls
Fluorescent lights (excitation of atoms)
Additives for sunscreens and cosmetics
Carbon nanotube additives to batteries
Latest generation of Intel chips
Any pattern or gross categories you see?