Download LECTURE # 1

3.052 Nanomechanics of
Materials and Biomaterials
LECTURE # 1 :
INTRODUCTION TO NANOMECHANICS
Prof. Christine Ortiz
DMSE, RM 13-4022
Phone : (617) 452-3084
Email : [email protected]
WWW : http://web.mit.edu/cortiz/www
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)
Nanostructured Materials
(*http://www.rpi.edu/dept/materials/COURSES/NANO/crawford/index.html)
Bone
Self-Assembling Monolayer
Nanoporous Alumina
Membrane
Nanostructured Materials
“Bottom-Up Manufacturing”
“Top-Down Manufacturing”
What is Nanomechanics ?
Summary of Length Scales (m)
hemoglobin
 6.6 nm
Biological
Sciences
quark
electron
atomic
nucleus
proton,
neutron
width of DNA,
small globular
proteins
 2 nm
atomic radii
covalent bond
 0.1 nm
smallest
observable feature
length of a
cell
of human eye,
blue whale
 50 mm thickness of
human hair
height of
bacteria,
Mt.
Everest
height of a
internal
grain of
 8848 m
human being
organelles
sand
 1m
 1 mm
size of
virus
of a bee
size of the
universe
diameter
of the
earth

10-18
10-16
10-14
10-12
10-10
10-8
10-6
10-4
10-2
100
102
104
106
1025

Materials
Sciences
size of C60 molecule,
diameter of
carbon nanotube,
suprmolecular chemistry,
colloidal particles,
nanolithography
microelectro
crystal mechanical
integrated length of a height of
grains systems
NYC
Boeing 767
circuit
(MEMS),
airplane World Trade
chip
radius of micro-contact
Center
traditional
printing,
AFM probe tip
man-made
integrated
materials and
circuit
structures
transistor
length
of the
Great Wall
of China
WHY STUDY
NANOMECHANICS ?
THREE EXAMPLES FROM BIOLOGY
Inflammatory Response :
Cell Rolling and Adhesion
Muscle Elasticity
(*MARSZALEK, et. al Nature 402, 100 - 103 (1999))
Nebulin
SARCOMERE
Myosin
Actin
(*Cell and Molecular Biology, G. Karp)
TITIN
TITIN
Packing the Genome
DNA
(*FEBS Lett. 371:279-282)
simulation
Packing the Genome
http://gened.emc.maricopa.edu/Bio/BIO181/BIOBK/BioBookCELL2.html
WHY STUDY
NANOMECHANICS ?
THREE EXAMPLES FROM MATERIALS SCIENCE
Performance of Computer Hard Disks
http://talke08.ucsd.edu/index/disk.html
Computer Head-Disk Interface
http://talke08.ucsd.edu/index/disk.html
suspension arm
recording head
2 mm
head flexure
surface
roughness
 30-60 nm
slider
read / write element
hard disk
flying height
 30-60 nm
Properties of Colloids
(*http://wintermute.chemie.uni-mainz.de/coll.html)
Silica sphere glued to an AFM-probe tip
Macroscopic Mechanical
Properties of Materials
Less Disorder
More Disorder
random coil
Entropy - a natural law that expresses the driving force towards disorder


F
Fchain
F
r
Fchain
F
F
Rubber Elasticity
s
Non-Linear, Entropic Elasticity
of Polymer Networks
l
A Typical
High-Resolution Force Spectroscopy Technique :
General Components
displacement
detection system
high-resolution
force transducer
d
prob
e
sample
high-resolution
displacement
control
z
sensor output
computer
• controls system
• performs data acquisition,
display, and analysis