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
· Tomlinson’s 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