3.04 / 3.072 Brief Summary of Lectures :
IMPORTANT NOTE :
Please come to lecture on time!
The most important part of the lectures is given in the first 15 minutes!
I will start lecture at exactly 5 minutes past the hour.

1. Introduction to Nanomechanics
2. Experimental Aspects of High Resolution Force Spectroscopy I
MOVIE : Feynman's Lecture on Nanotechnology (1984) : "Tiny Machines"
3. Experimental Aspects of High Resolution Force Spectroscopy II
4. Qualitative Introduction to Intra- and Intermolecular Forces
5. Quantitative Description of Intra- and Intermolecular Forces
6. Interparticle and Intersurface Forces
7. Electrostatic Interactions Between Surfaces in Liquids
8. Review for Exam #1
EXAM #1
9. Adhesion and Contact Mechanics I
10. Adhesion and Contact Mechanics II
11. Nanoindentation (Guest Lecturer : Prof. Subra Suresh, MIT, DMSE)
12. Theory of Elasticity of Single Macromolecular Chains : The Freely-Jointed Chain (FJC) Model
13. Nanomechanics of Synthetic Polymers
14. Nanomechanics of Biopolymers
15. Review For Exam #2
EXAM #2
18. Dynamic Force Spectroscopy : Nanorheology, Nanoconfinement,and Force Modulation (Guest Lecturer : Prof. Nancy Burnham, WPI, Physics)
LABORATORY : High-Resolution Force Spectroscopy Simulations
16. Intermolecular Interactions of Polymers
17. Chemical Force Microscopy (CFM)
18. Bond Strength Measurements
19. Directed Motion of Biological Structures : Molecular Motors
20. Molecular Basis for Biological Motility(Guest Lecturer : Prof. L. Mahadevan, MIT, MECHE)
21. Atomistic Aspects of Fracture
22. Lateral Forces at the Atomic Scale : Friction
EXAM #3

Detailed Summary of Lectures :

manifestations in macroscopic mechanics (rubber elasticity)

Number

Material Covered

Readings

1

Introduction to Nanomechanics :
what is nanomechanics?
historical background
summary of length scales compared for biology and materials science
nanotechnology
four fundamental forces of nature
summary of force scales compared for biology and materials science
why is nanomechanics important to study? (*movies)

Israelachvili, pgs. 3-15, 27-29
Feynman's Classic Nanotechnology Talk (1959, APS-Caltech); "There's Plenty of Room at the Bottom"
"Engines of Creation : The Coming Era of Nanotechnology," Chapter 1, K. Eric Drexler, Doubleday, 1986.

2

Experimental Aspects of High- Resolution Force Spectroscopy : I
introduction to high-resolution force spectroscopy
description of general components and function of each component
force transducers
cantilever beam theory
force sensitivity
fundamental physical limits of force detection : harmonic oscillators
Ortiz handouts : (1) review / summary of cantilever beam theory, (2) summary of harmonic motion, and (3) limits of force detection
Handouts from "Vibrations and Waves,"A. P. French, W. W. Norton and Company, 1971.

3

Experimental Aspects of High-Resolution Force Spectroscopy : II
displacment detection : Optical Lever Deflection Technique
displacment control : piezoelectrics
force versus distance curves and conversion of raw data
force transducer instabilities
statistical analysis of force curves
atomic force spectroscopy
optical and magnetic tweezers
surface forces apparatus
biomembrane surface probe
glass microneedles and micropipets
magnetic resonance force microscopy
magnetic rheometry
comparison of force detection limits and force ranges
Handouts from Physik Instrumente, Inc., "Basic Introduction to Nanopositioning with Piezoelectric Technology"
Israelachvili, pgs. 168-174

4

Qualitative Introduction to Intra- and Intermolecular Forces :
covalent
metallic
ionic (i.e. charge-charge)
polar interactions (e.g. charge-dipole, dipole-dipole, hydrogen bonding)
polarization interactions (e.g. charge-nonpolar, dipole-nonpolar)
dispersion or london interactions (i.e. nonpolar-nonpolar)
special interactions (e.g. hydrophobic, hydrophilic, entropic elasticity)
Handouts from Cell and Molecular Biology, G. Karp, 1991.
Israelachvili, Sections 3.1, 3.2, 3.4, 4.1, 4.3, 4.7, 6.1, 6.2, 7.1, Chapter 8

5

Quantitative Description of Intra- and Intermolecular Forces :
intra- and intermolecular potentials, forces, and stiffnesses : general mathematical form
noncovalent van der Waals interactions-Lennard-Jones potential
covalent interactions- Morse potential
harmonic approximation
thermal expansion
comparison of potentials for different types of interactions
comparison of binding energies for different types of interactions
comparison of interaction distance ranges for different types of interactions
same as above

6

Interparticle and and Intersurface Forces :
bridging the gap between length scales
derivation of interaction potential between a molecule and flat surface
derivation of interaction potential between a sphere and flat surface
derivation of interaction potential between two flat surfaces
summary of dispersion van der Waals interaction potentials
comparison with experimental data
retardation effects in dispersion van der Waals interactions
Israelachvili, Sections 6.9, 10.1-10.3, 11.1, 11.2

7

Electrostatic Interactions Between Charged Surfaces in Liquids
the electric double layer
the interaction between charged surfaces in solution : the contact value theorum
the interaction between charged surfaces in the presence of an electrolyte
DLVO theory
Israelachvili, Sections 12.1-8, 12.11, 12.15-18

8

Review for Exam I

9

Adhesion and Contact Mechanics : I
work of adhesion
Hertz theory
Derjaguin, Miller, Toporov (DMT) theory
Burnham-Colton-Pollack (BCP) theory
Chapter 15, Israelachivili

10

Adhesion and Contact Mechanics : II
Johson-Kendal-Roberts (JKR) theory
introduction to nanoindentation
elastic-to-plastic deformation
Chapter 15, Israelachivili

11

Nanoindentation :
load versus indentation curves of various materials :
linear elastic (e.g. diamond)
nonlinear elastic (e.g. rubber, cell membranes, bacterial cell walls)
rigid-plastic (e.g. metals)
elastic-plastic and strain-hardening (e.g. metals, polymers)
elastic-brittle (e.g. ceramics, glasses)
estimation of local mechanical properties (e.g. hardness, stiffness, yield, work of indentation, hysteresis, fracture toughness)
N/A

12

Theory of the Elasticity of Single Macromolecular Chains : The Freely-Jointed Chain (FJC) Model
assumptions and definitions (e.g. statistical segment length, contour length, root-mean- square end-to-end distance)
general statistical mechanical formulas
Gaussian chain statistics
non-Gaussian chain statistics
extensibility
effect of a and n on force curves
Ortiz handouts

13

Elasticity of Single Macromolecular Chains : Cont'd
the worm-like chain (WLC) : assumptions and definition of persistance length
extensibility and comparison with FJC
comparison of theory with experimental data on synthetic polymer chains (e.g. PS, PMAA, PEG, PVA)
statistics of adsorption of polymer chains to surfaces
Ortiz handouts

14

Elasticity of Single Macromolecular Chains : Biopolymers
Markovian two-state thermodynamic models
polysaccharides (e.g. Dextran, Xanthan, cellulose)
elasticity of globular proteins (e.g. Titin, Tenascin)
N/A

15

Elasticity of DNA :
review of DNA structure
theory and experiment
single-stranded
double-stranded (e.g. B-DNA to S-DNA strain-induced conformational transition)
ionic effects
torsional constraints (e.g. overwound "supercoiled" P-DNA and underwound)
braided energy of denaturation (melting)
sequence-dependent mechanics
molecular knots
reptation (theory and experiment) and relaxation of stretched DNA
molecular separation of complementary strands of DNA
TBA

-

Lateral Forces at the Atomic Scale : Friction :
topographical effects
Tomlinsonís model
friction between atomically flat surfaces
stick-slip
frictional force microscopy (e.g. self-assembled monolayers)
Handouts from Nanoscience : Probing Friction and Rheology on the Nanometer Scale, Eds. E. Meyer, T. Gyalog, R. M. Overney, K. Dransfeld, World Scientific Publishers, 1999.

-

Chemical Force Microscopy (CFM) :
self-assembled monolayers with uncharged functional groups
self-assembled monolayers with charged functional groups
protein-SAM CFM
TBA

-

Intermolecular Interactions of Polymers :
structure of polymers at surfaces : effect of grafting density (e.g. brushes, mushrooms), effect of grafting type (e.g. physisorbed, chemisorbed, telechelic)
segment density versus distance plots (simulations)
Alexander-de Gennes theory
effect of temperature (relative to q-temperature) on force versus distance profiles
comparison to experiment (e.g. PS, PEO, polyelectrolytes)
TBA

-

Dynamic Force Spectroscopy : Nanorheology, Nanoconfinement, and Force Modulation :
theoretical background, comparison with experimental data (e.g. polymer brushes)
lubrication (e.g. disk drives)
force modulation mapping (e.g. composites, polymer blends, biological materials)
TBA

-

Bond Strength Measurements (1) :
biomembrane surface probe
introduction to biomolecular adhesion (ligand-receptor interactions) and relevance to cell adhesion
reaction-rate theory, theory of molecular kinetics under force in liquids
theory of force distributions in probe experiments
TBA

-

Bond Strength Measurements (2) :
energy landscapes :
biotin-strept(avidin)
carbohydrate-L-selectin
anchoring strength of lipids in membranes
serial linkages
rupture of bonds connected to flexible polymer chains
rupture of covalent bonds
TBA

-

Directed Motion of Biological Structures : Molecular Motors (1) :
general overview : chemical, mechanical, and electrical
Brownian Motion
why are they needed?
TBA

-

Directed Motion of Biological Structures : Molecular Motors (2) :
force velocity measurements
kinesin-microtubule (*movie)
acto-myosin
DNA transcription by RNA polymerase
bacterial flagella
TBA

-

Atomistic Aspects of Fracture :
summary of relevant length scales in fracture mechanics
derivation of theoretical cleavage stress and comparison with experimental data
molecular dynamics simulations (movies)

TBA