3.052 Nanomechanics of

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3.052 Nanomechanics of Materials and
Biomaterials
LECTURE 1 INTRODUCTION TO NANOMECHANICS
Prof. Christine Ortiz DMSE, RM 13-4022 Phone
[phone] Email cortiz_at_mit.edu WWW
http//web.mit.edu/cortiz/www
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Basics of Nanotechnology
Nanostructure
Broad Definition
Specific Definition Molecular Manufacturing
Electron-microscope image of the world's
smallest guitar, based roughly on the design for
the Fender Stratocaster, a popular electric
guitar. Its length is 10 millionths of a meter--
approximately the size of a red blood cell and
about 1/20th the width of a single human hair.
Its strings have a width of about 50 billionths
of a meter (the size of approximately 100 atoms).
Plucking the tiny strings would produce a
high-pitched sound at the inaudible frequency of
approximately 10 megahertz. Made by Cornell
researchers with a single silicon crystal, this
tiny guitar is a playful example of
nanotechnology, in which scientists are building
machines and structures on the scale of
billionths of a meter to perform useful
technological functions and study processes at
the submicroscopic level. (http//www.news.cornell
.edu/science/July97/guitar.ltb.html, Dustin W.
Carr and Harold G. Craighead, Cornell.)
Readings 1. "There's Plenty of Room at the
Bottom," Richard P. Feynman's Classic
Nanotechnology Talk (1959, APS-Caltech) 2.
Engines of Creation The Coming Era of
Nanotechnology, K. Eric. Drexler, Anchor Books,
Doubleday, 1986 (Chapter 1)
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Nanostructured Materials (http//www.rpi.edu/dept
/materials/COURSES/NANO/crawford/index.html)
Bone
Self-Assembling Monolayer
Nanoporous Alumina Membrane
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Nanostructured Materials
Bottom-Up Manufacturing
Top-Down Manufacturing
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What is Nanomechanics ?
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Summary of Length Scales (m)
hemoglobin ? 6.6 nm
smallest observable feature of human
eye, thickness of human hair
length of a blue whale
Biological Sciences
cell ? 50 mm
width of DNA, small globular proteins ? 2 nm
size of the universe
height of Mt. Everest ? 8848 m
bacteria, internal organelles ? 1 mm
height of a human being ? 1m
grain of sand
diameter of the earth
quark
atomic nucleus
atomic radii covalent bond ? 0.1 nm
proton, neutron
size of of a bee
virus
electron
?
10-18
10-16
10-14
10-12
10-10
10-8
10-6
10-4
10-2
100
102
104
106
1025
?
size of C60 molecule, diameter of carbon
nanotube, suprmolecular chemistry, colloidal
particles, nanolithography
microelectro mechanical systems (MEMS), micro-con
tact printing, integrated circuit transistor
length of the Great Wall of China
crystal grains
height of NYC World Trade Center
length of a Boeing 767 airplane
integrated circuit chip
Materials Sciences
radius of AFM probe tip
traditional man-made materials and structures
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WHY STUDY NANOMECHANICS ? THREE EXAMPLES FROM
BIOLOGY
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Inflammatory Response Cell Rolling and Adhesion
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Muscle Elasticity
(MARSZALEK, et. al Nature 402, 100 - 103 (1999))
SARCOMERE
TITIN
Actin
TITIN
Nebulin
Myosin
(Cell and Molecular Biology, G. Karp)
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Packing the Genome
DNA
simulation
(FEBS Lett. 371279-282)
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Packing the Genome
http//gened.emc.maricopa.edu/Bio/BIO181/BIOBK/Bio
BookCELL2.html
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WHY STUDY NANOMECHANICS ? THREE EXAMPLES FROM
MATERIALS SCIENCE
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Performance of Computer Hard Disks
http//talke08.ucsd.edu/index/disk.html
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Computer Head-Disk Interface
http//talke08.ucsd.edu/index/disk.html
suspension arm
recording head
2 mm
surface roughness ? 30-60 nm
head flexure
slider
flying height ? 30-60 nm
read / write element
hard disk
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Properties of Colloids
(http//wintermute.chemie.uni-mainz.de/coll.html)
Silica sphere glued to an AFM-probe tip
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Macroscopic Mechanical Properties of Materials
Less Disorder
More Disorder
random coil
Entropy - a natural law that expresses the
driving force towards disorder
?
F
F
?
r
Fchain
Fchain
F
F
s
Rubber Elasticity
Non-Linear, Entropic Elasticity of Polymer
Networks
l
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A Typical High-Resolution Force Spectroscopy
Technique General Components
high-resolution force transducer
sensor output
d
computer controls system performs data
acquisition, display, and analysis
probe
sample
high-resolution displacement control
z