Transcript Mohammad Tavakoli - Nanotechnology

Mohammad Tavakoli
4th Mini-Seminar in Physiology of Brain & Cognition
Instructor: Dr. Gharibzadeh
Spring 2008
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Atomic Technology:
 Concerning Energy

Biotechnology & Stem Cells:
 Concerning Life & Health

IT:
 Concerning Information

Nanotechnology:
 Concerning Very Small Things ;)

How small would it be?
 Millimeter:
▪ Wavelength of microwaves
 Micrometer:
▪ One millionth of a meter
 Nanometer:
▪ One thousand millionth of a meter
 Angstrom:
▪ Hundred-millionth of a centimeter or 10-10 meter
▪ Wavelength of light: 400 to 700 nanometers or .4-.7 Å

Submicroscopic things and phenomenon are not
visible in analytical manner!
 Brownian motion in fluids -> Chaotic Environment
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So What?
Computational Science
 Prof. Rafii-Tabar (IPM)
 Simplification & Idealization
 Numerical Modeling (Abstract) & Computer Simulation
 Supercomputers & Parallel Processing
 Physics of Nanotechnology: 10-15 sec. & 10-7 -10-9 m.

Scanning Tunneling Microscopy (STM)
 IBM (1980)
 Simulations @ IBM website, e.g. Nano-tubes

Atomic Force Microscopy (AFM)
 Seeing like a blind person
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Magnetic Resonance Force Microscopy
 The technique used here is same as MRI
 Academic researches


In AFM, a sharp probe is scanned across a surface,
left, and by monitoring the motion of the probe
from each pass across the surface, a 2-D line profile
is generated.
Then the line profiles are combined to create a
three dimensional image of the surface, right.
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Quantum:
 Gaussian
 Wein2K
 Spresso
 GPMD

Molecular Dynamics:
 NAMD

Visualization:
 AVS
 VMD (Visual Molecular Dynamics)

Nanomagnetic Structures
for Atomic Resolution MRI
 Nanowire-based sensor for
ultra-high sensitivity
magnetic resonance force
microscopy
 Amplification of magnetic flux
in magnetic resonance by
magnetic nanoparticles that
promises to significantly
improve MRI performance
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Problem 1:
 In 2001 a patient in a British hospital died of heart failure
shortly after being given an MRI brain scan!

Solution:
 “Nano-coated implants cut MRI scan dangers” 2003
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Problem 2:
 How can we improve the MRI resolution?
 Solution: Contrast Agents
 What can Nanotechnology do here?
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Solution:
 Superparamagnetic contrast agents (e.g. iron oxide
nanoparticles) have become available.
 These agents appear very dark on T2*-weighted images
and may be used for liver imaging - normal liver tissue
retains the agent, but abnormal areas (e.g. scars,
tumors) do not.
 They can also be taken orally, to improve visualization of
the gastrointestinal tract, and to prevent water in the
gastrointestinal tract from obscuring other organs (e.g.
pancreas).
71.8
With Nanoparticles
Without Nanoparticles
Micro-Coil Voltage (micro-Volts)
71.6
71.4
71.2
71.0
70.8
70.6
70.4
70.2
70.0
0
1000
2000
3000
4000
Magnetic Field (Gauss)
5000
6000
The End