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• Nano wires Nano devices

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What is nanotechnology?
1n
0.1n
10n
100n
1m
10m
100m
1cm
1m
H2O
DNA
Virus
White blood cell
Human hair
NEMS/MEMS

• Nano devices
• Nano tubes
• Nano transistors
• Quantum dots
• ...

No sharp Frontiers!
100m
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Why is it special?

• Ability to act on phenomena
• previously uncontrolled
• Physical properties
• Chemical reactions
• Biological transformations

This lecture is mainly about Potentials AND
Risks
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How is it fabricated?
Two approaches
Top down
Bottom up
(self ) Assembling tiny objects into Nano devices
Cutting a nano piece out of a bulk (used in
microelectronics)
H-bond
DNA-like molecules
Assembles to
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Top Down main processes

• Lithography
• Photolithography
• Electron beam lith.
• Ion implantation
• Thermal treatment
• Etching
• Wet etching
• Dry etching
• Deposition
• Chemical Vapor Dep. CVD
• Physical Vapor Dep. PVD

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Top Down example a nano-switch 1
Patterning
2-Photolithography
1-LPCVD Si3N4-125n
Photo-resist
Si-125m
3-Reactive Ion Etching RIE (He SF6)
Exposing
4- Wet Etching (KOH)
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Top Down example a nano-switch 2
6-Resist Deposition of Cr (60n) Electron beam
lithography
5-Patterning
1m
7- Deposition of Cr (5n) Au (70n)
8-RIE
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Carbon Nano Tubes (CNT)
Take a sheet of carbon atoms
Roll it!
Carbon Nano Tube Strength 100 x Steel Weight
1/6 x Steel
You still need to assemble many of them to be
useful!
Prof. Richard Smalley (Rice U.) it would take a
single nanoscopic machine millions of years to
assemble a meaningful amount of material.! Eric
Drexler believes assemblers could replicate
themselves, resulting in exponential growth.
http//science.howstuffworks.com/nanotechnology4.h
tm
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Bottom Up example a cantilever
Cantilever beam material
Creating cantilever structure
Fe2O3 nano particles
Polyelectrolyte
CNT
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Biomedical Applications
Lab on a chip
Manipulating drops (micro-fluidic) (video)
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Detecting Molecules
Artificial nose!
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Drug delivery systems
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Nano devices are smaller than cells
Nano devices can easily enter in cells for
early detection of cancer In vivo
Cell size 1 2 m
National Cancer Institute
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More efficient cancer test
National Cancer Institute
Each cantilever can capture one specific type of
molecules
Cantilever bending electronically detected
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Nano-pores help reading DNA code
Nano-pores DNA passes through one strand at a
time, DNA sequencing more efficient. Monitor
shape electrical properties of each base,
or letter, Hence, decipher the encoded
information, including errors associated
with cancer.
National Cancer Institute
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Nano-pores in Aluminum
100 n
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Using CNT to detect DNA defects
A Nano-tube (sharp edged pin) Traces the shape of
DNA, making a map
National Cancer Institute
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Using quantum dots to detect cancer
Quantum dots
Crystals (few nm) with size dependent optical
properties UV stimulus They glow (size dependent
color) Can be designed to bind to specific DNA
sequences. (to detect and treat cancer cells)
National Cancer Institute
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Dendrimers the complete solution!
Cancer Cell
Cancer detector
Drug
Cancer detector
Cell death Monitor
Dendrimers
Man-made molecules ( a protein). Shape gives
vast amounts of surface area Can attach
therapeutic agents or other biologically active
molecules.
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Programmable nano robots!
A near future dream! Patients will drink fluids
containing nano-robots programmed to attack and
reconstruct the molecular structure of cancer
cells. Nanorobots could also perform delicate
surgeries more precise than the sharpest
scalpel source International Journal of
Surgery
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Nano for Energy
4th Generation Solar Cells
Fuel Cells
Energy Harvesting
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Solar Energy
World electric power demand 14
TW Incident Solar power
120, 000 TW!! Consider 10 efficiency, exclude
oceans and cities 600 TW
Average extractable power from Egyptian desert
alone 15 TW
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Solar energy economics
Not only efficiency matters, but also cost!
Prof. Rastogi, Binghamton U.
Expected grid parity year 2012 2018 (depending
on region) source iSupply Applied Market
Intelligence
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Nano pillars for solar cells
Radiation losses due to reflection
Anti Reflection Coating Using Nano Pillars
900n
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Thin film solar cells
Prof. Rastogi, Binghamton U.
Thin film ? small amount of Si (amorphous Si) ?
Low initial price Flexible ? low installation
cost
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Quantum dots for solar cells 1
Conduction band
Energy Band gap
Incident Photons
Donors level
Electrons
Losses for both too high and too low energy
photons
Need to have adjustable band gaps ??
Valence band
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Quantum dots for solar cells 2
Conduction band
Energy Band gap
For Quantum dots Band Gap is size dependent
Make many sizes to capture all incident
photons Small size Highly excited electron
can share energy with another one
Valence band
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Fuel cells
Fuel can be H2 or other hydrocarbons
Heat (85oC)
Membrane (heart of the device) passes H ions only
Platinum catalysts
Can power Handheld devices Up to trucks
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Environmental impact of burning fuel
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Nano improvements of fuel cells

• Higher efficiency membrane
• Higher surface area and lower quantity of
  catalyst (Platinum)
• New less expensive catalyst materials

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Energy harvesting Thermo-ionic effects
DV (open circuit) S (Thot Tcold)
S Seebeck Coefficient

• Materials A B can be
• Two different metals
• Semiconductors with different doping

When connected to a load
DV
W h Qhot h lt 1 Tcold/Thot
Material B
Material B
Power W (W)
h increases with S, s (elec cond) h decreases
with k (thermal cond)
Material A
Thot
Tcold
Figure of merit Z S2 s/k
Metal/Semiconductor Nano composites Very High Z
Heat Qcold (W)
Heat Qhot (W)
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Nanopiezotronics
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Energy harvesting nano brush
Zinc oxide nano wires
4-layer integrated nano generator Output power
0.11 µW/cm2 at a voltage of 62 mV.
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Nano Electronics is here since long!
A transistor
Oxide thickness 10n
Gate
Source
Drain
Channel length lt 45 nano
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Major problem heat!
The growing power density (measured in W/cm2) of
Intel's microchip processor families. (Source
Intel)
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RD issues in thermal effects

• Modeling Simulation
• Multiple Physics (Mainly Electro-thermal)
• Multiple Scales (transistor ? data center )
• Compact Thermal Models
• New technology for multiple source problems
  3D ICs, SoC
• High performance simulation/optimization tools

• Micro-fluidics micro heat transfer
• Micro-channels
• Micro effects in 2 phase Electro
  wetting/micro-boiling
• Integrated micro/nano coolers

• TACS Temperature Aware Computer Systems
• Thermal aware layout
• Thermal aware operating systems (ex scheduling
  )

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Other RD trends

• Flexible flat display panels using nanowires
• NEMS for high density memory (terabyte/ in2)
• Molecular sized transistors
• Self aligned nanostructures to build integrated
  circuits

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Nanotechnology impact on environment
Pros

• A high potential for new and renewable energies
• Less CO2 emission
• A high potential for pollution detection
• A high potential for water treatment
• Composition detection
• Desalination
• Waste water treatment
• Solution of many health problems

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BUT !
Nanoparticles may accumulate in vital
organs, creating a toxicity problem.

• Use of toxic, basic or acidic chemicals organic
  solvents
• 99 of materials used are not in final product
• Actual manufacturing of nanodevices is highly
  energy intensive
• Unknown impact of nanoparticles on natural cells

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Conclusion

• Nanotechnology is not the future, it is
• the present and the near future
• Nanotechnology has highly promising applications
  in almost all engineering, medical, environmental
  issues.
• It is inherently multi-disciplinary
• Side effects, potentially harmful, are not yet
  quite well assessed.

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• app_micro_drop_merge.avi
• app_micro_Tjunction3D.avi