Transcript smile_workshop_v4 - College of Science | Oregon State University

Nanotechnology
workshop
Ethan Minot, Department of Physics, Oregon State University
[email protected]
(Please send me an email – I’d love to hear from you)
1
Web links
All videos that I showed in this presentation at listed and hyperlinked at:
http://www.science.oregonstate.edu/~minote/wiki/doku.php?id=2012_smile_workshop
Overview
3
Orient ourselves in the nanometer world using
biological examples
Nature makes builds everything from the bottom up (assemble the constituent atoms)
2 nm
Single stranded dna goes in
Double stranded dna comes out
In contrast, engineers often start with a big material and cut it smaller
5
Activity: Cutting it down to nano
Acknowlegdement: U. Wisconsin, MRSEC
Video http://vimeo.com/15540606
Keep cutting in half until you make “nanopaper”!
See how many times you can cut in half.
(Keep count).
6
Activity: Cutting it down to nano
Acknowlegdement: U. Wisconsin, MRSEC
Video http://vimeo.com/15540606
Keep cutting in half until you make “nanopaper”!
See how many times you can cut in half.
(Keep count).
How many more times are needed?
(try calculating).
What tools are needed?
Another math question: If the paper dimensions are h x w,
what ratio h/w should I choose so that h/w is invariant?
7
Milling (old-school)
2 cm
A milling machine in a standard workshop
8
Focused ion beam milling
http://nanotechweb.org/cws/article/tech/37573
http://en.wikipedia.org/wiki/Focused_ion_beam
Video of ion mill: http://www.jcnabity.com/fibmill1.htm
9
Other ways to make
tiny patterns
Direct write laser lithography
($500,000)
Direct write electron beam lithography
($500,000)
Image projection photolithography
($5,000,000)
10
Why spend 5 million?
10 nm
Cartoon picture
Real image:
TEM cross-section of a Tri-Gate Transistor
11
Why go small?
1. Miniturization:
- More transistors on a chip
- More memory in an iphone
- Test smaller blood samples from a patient
- Use less chemicals in a chemistry experiment
…
2. Maybe the material will take on new properties?
12
New properties at the nanoscale
2010 Nobel Prize in Physics:
Geim and Novoselov cut graphite down to
the nanoscale and “discovered” graphene
Did they use a focused ion beam,
or a projection lithography system,
or a biologically inspired self-assembly technique?
13
New properties at the nanoscale
2010 Nobel Prize in Physics:
Geim and Novoselov cut graphite down to
the nanoscale and “discovered” graphene
Did they use a focused ion beam,
or a projection lithography system,
or a biologically inspired self-assembly technique?
14
Activity: Cutting graphene down to the nanoscale
0.34 nm
0.14 nm
15
Graphite:
Graphene:
Electrons travel a few
nanometers before
scattering
Electrons travel a 100 nm
before scattering
Electrons velocity can
be anything from zero
to 106 m/s
Electrons move at a
single velocity, 106 m/s.
(Similar physics as
photons – photons can
only move at 3 x 108 m/s)
16
The size threshold for nanoscience
Other famous examples… gold, silver and aluminum
Google search for “Nano and me youtube”
Can relate this idea to the resistivity of materials.
Resistivity is an intrinsic property that will change at the nanoscale).
Bulk playdough has a resistivity ~ 20 Ohm.cm
17
The size threshold for nanoscience
Big
Small
.
Physical and chemical properties
start to smoothly change
Billions of atoms
Gradual
transition to
the nanoscale
1 atom
18
Scientific curiosity, or something useful?
What could I do with a cheap, high performance electronic material
that also happens to be transparent and chemically inert?
For more ideas, google
“A Day Made of Glass” movie by Corning
19
3rd dimension of periodic table
s
Size & geometry
20
Pathway to consumer electronics
Not practical
Very practical!
21
Activity: Act out the assembly process
Methane molecules absorb to
the copper surface. At high
temperature the methane
flattens out. Carbon-carbon
bonds start to form in the
plane. The process is selflimiting when the copper is
covered. H2 is released.
Look for this candy in the bulk bin at WinCo. $3 per pound.
22
Summary
Cut down
Build up
23
Historical note: 1989 was an important milestone
In 1989, Don Eigler was the first to use a
scanning tunneling microscope tip to
arrange individual atoms on a surface,
famously spelling out the letters "IBM" with
35 xenon atoms.
- See wikipedia article on Don Eigler
24
Making a CNT circuit
A good point to explain the research that I do.
Assemble atoms
Micromachining of metal electodes
(photolithography)
25
Assemble atoms into a carbon nanotube
Furnace: 900oC
methane
Substrate
Quartz substrate
26
Micromachining metal electrodes
3.
2.
1.
Furnace: 900oC
Substrate
4.
Rachel and Claire,
2010 SESEY Camp
27
Hands-on analogy to making metal electrodes
1.
2.
3.
4.
28
Compare to nanoelectronics lab
methane
Furnace: 900oC
Substrate
Seed
29
Compare to nanoelectronics lab
$300,000 laser lithography tool
30
Compare to nanoelectronics lab
$100,000 metal deposition tool
•Crucible with molten gold.
•Pressure inside chamber
same as outerspace
31
Compare to nanoelectronics lab
10 cm
$200,000 microscope
10 mm
32
Compare to nanoelectronics lab
33
What are these circuits good for?
Replace the silicon (colored
yellow) with a carbon nanotube
Amplify electronic to noise made by
a single enzyme.
Many more examples…
34
Why listen to the noise of single enzyme?
“Everything that living things do can be
understood in terms of the jigglings and
wigglings of atoms” - Richard Feynman
35
How can I tell if there is a single enzyme on a CNT?
36
Old technology isn’t appropriate
Light microscope
photon
Single enzyme
diameter ~ 5 nm
.
wavelength ~ 500 nm
3 nm
37
Eyes at the nanoscale
Scanning probe techniques
Atomic force microscopes
Scanning tunneling microscopy
Electron microscopy
Scanning electron microscope
Transmission electron microscope
38
Atomic force microscopes
39
Imaging examples
For educational purposes, an atomic force
microscope (AFM) was put inside a scanning
electron microscope (SEM) to show the working
principles of the AFM. In practice, the AFM is
higher resolution than the SEM.
This AFM video shows single stranded pieces
of dna lying on a smooth surface. Brownian
motion is causing the dna to “wiggle and jiggle”.
40
Activity: Atomic Force Microscope
41