3.052 Nanomechanics of Materials and Biomaterials
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Transcript of 3.052 Nanomechanics of Materials and Biomaterials
3.052 Nanomechanics of Materials and Biomaterials
Prof. Christine OrtizDMSE, RM 13-4022
Phone : (617) 452-3084Email : [email protected]
WWW : http://web.mit.edu/cortiz/www
LECTURE # 1 : INTRODUCTION TO NANOMECHANICS
Basics of Nanotechnology
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)
Specific Definition :“Molecular Manufacturing”
Broad Definition :
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.)
“Nanostructure”
Nanostructured Materials(*http://www.rpi.edu/dept/materials/COURSES/NANO/crawford/index.html)
Bone
Self-Assembling MonolayerNanoporous Alumina
Membrane
Nanostructured Materials
“Bottom-Up Manufacturing”
“Top-Down Manufacturing”
What is Nanomechanics ?
Summary of Length Scales (m)
Biological Sciences
Materials Sciences
10-16 10-14 10-12 10-10 10-8 10-6 10-4 10-2 100 102 104 106 1025
atomic radiicovalent bond
0.1 nm
width of DNA,small globular
proteins 2 nm
hemoglobin 6.6 nm
bacteria,internal
organelles 1 m
cell 50 m
height of a human being
1m
length of a blue whale
height of Mt. Everest 8848 m
diameter of theearthsize of
of a bee
atomicnucleus
proton,neutron
virus
radius of AFM probe tip
size of C60 molecule,diameter of
carbon nanotube,suprmolecular chemistry,
colloidal particles,nanolithography
microelectromechanical
systems(MEMS),
micro-contact printing,
integratedcircuit
transistor
length of a Boeing 767
airplane
height of NYC
World Trade Center
quark
traditionalman-made
materials andstructures
lengthof the
Great Wallof China
size of the universe
10-18
electron
crystal grains
smallest observable feature
of human eye,thickness ofhuman hair
integratedcircuit
chip
grain ofsand
WHY STUDY NANOMECHANICS ?
THREE EXAMPLES FROM BIOLOGY
Inflammatory Response :Cell Rolling and Adhesion
Muscle Elasticity
(*MARSZALEK, et. al Nature 402, 100 - 103 (1999))
(*Cell and Molecular Biology, G. Karp)
SARCOMERE
TITINActin TITINMyosinNebulin
Packing the Genome
DNAsimulation(*FEBS Lett. 371:279-282)
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 Diskshttp://talke08.ucsd.edu/index/disk.html
Computer Head-Disk Interface
2 mm
sliderhead flexure
suspension arm
flying height 30-60 nmread / write element
hard disk
recording head
surface roughness 30-60 nm
http://talke08.ucsd.edu/index/disk.html
Properties of Colloids
Silica sphere glued to an AFM-probe tip
(*http://wintermute.chemie.uni-mainz.de/coll.html)
Macroscopic Mechanical Properties of Materials
Non-Linear, Entropic Elasticity of Polymer Networks
Rubber Elasticity
FrFchain
Fchain
F
F
F
More Disorder Less Disorder
Entropy - a natural law that expresses the driving force towards disorderrandom coil
A Typical High-Resolution Force Spectroscopy
Technique : General Components
sensor output
sample
high-resolutionforce
transducer
displacement detection
system
high-resolution
displacement control
computer• controls system
• performs data acquisition, display, and analysis
z
probe