lecture 1 why is nano-scale special

8/9/2019 Lecture 1 Why is Nano-scale Special

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Mechanics of Nanomaterials (Ae 244)

Instructors: Chiara Daraio & Julia Greer

California Institute of Technology

Chiaras contact: [email protected] contact: [email protected]

Office hours: by appointment

Class meets: Tuesday and Thursday in 308 Firestone From 2-3.30pm

Class webpage: http://www.its.caltech.edu/~msjang/TA: Jang, MinSeok, [email protected]


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Ae 244. Course Description

This course will cover the basics of the mechanics of both nano-structures and nano-structured materials.

Synthesis and processing methods,

analytical characterization techniques, resulting material properties and applications will be covered.

The emphasis will be on relation between microstructural and mechanicalproperties.Specifically, the course will give an overview of properties ofnanostructured metals/ceramics/composites, nanowires, nanotubes,quantum dots, and nano-particles with their applications in electronics,sensors, and bio-medicine.

Innovative experimental methods and microstructural characterizationtechniques developed for studying nanoscale phenomena will bedescribed.Recent advances in the application of nanomaterials in engineeringsystems and IP-related aspects of nano-materials will also be covered.


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Master Schedule and Outline (Ae 244)

JuliaFIBCharacterizationWeek5/Oct. 30

Force-based techniques: AFM, Nanoindentation,

SPM

JuliaWeek5/Nov. 1

ChiaraWeek 4/Oct. 25

Chiara1) Electron scattering overview2) E-scattering based techniques overview: SEM(BS, SE, EBSD), EDS (FIB)

CharacterizationWeek 4/Oct. 23

JuliaWeek 3/Oct. 18

JuliaMicro-fluidics, fuel cells, biomedical, bio-mimickingflexible electronics, solar cells, PVs

ApplicationsWeek 3/Oct. 16

JuliaWeek 2/Oct. 11

ChiaraBottom UpTop Down

SynthesisWeek 2/Oct. 9

JuliaWeek 1/Oct. 4

ChiaraWhy is nano-scale special?How are nano-materials different?Definition of nanostructures, nanostructured materials, nanoscale precipitates

IntroWeek 1/Oct. 2

InstructorTopicSectionWeek/Date


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Master Schedule and Outline (Ae 244)

JuliaQuantum Effect, transport, Field emission,thermal, magnetic, chemical, Optical

PropertiesWeek 7/Nov. 13

ChiaraStudents final presentationsWeek 10/Dec. 6

ChiaraExperimental methods: New methods for nanomechanicsWeek 10/Dec. 4

Guest Lecture on Atomistic Simulations for Nanomaterials WAG IIIWeek8/Nov. 20

TA/ChiaraField trip to labsField trip to labsWeek 9/Nov. 29

Chiara Nanostructured: Hall Petch, nanograinsPropertiesWeek 9/Nov. 27

THANKSGIVINGWeek 8/Nov. 22

Week 7/Nov. 15 Proposal/Patent writing Chiara

ChiaraMechanical properties Special on Nanotubes: defects, deformations, dynamics

Week 6/Nov. 8

JuliaMechanical properties 1 Buckling,Dislocation, plasticity in nanostructures

Week 6/Nov. 6 Properties


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Class Requirements and grading scheme

1 midterm (take-home exam),

1 patent application,

1 final project (mini-proposal)

HWs: ~4 expected, one on each major topic (intro/synthesis,

characterization, properties, applications)

1 field trip to visit all the labs

GRADING %

30 %

20 %

20 %

30 %

100 %


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CLASS POLICIES

Zero tolerance on late homework assignments (no credit given for late HWs)

4 homework assignments (due every other Friday starting Oct. 12 th)

Collaborative HWs solutions are NOT an option, though students are welcome and

encouraged to discuss among themselves.

Midterm is a take-home, open books and notes.

Provisional patent application exercise to be completed individually.

Final project (Mini Proposal) to be prepared in small groups (2-3 students max).


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COURSE OBJECTIVES

Understanding nanomaterials: synthesis, properties and applications in multiple

engineering fields.

Study how the structure of materials can be controlled down to the nanometer scale

through various processing methods.

Study structure-property relationships at the nanoscale.

Study applications involving nanostructured materials, patenting issues and grant writing.

Develop effective interdisciplinary communication skills.

Critically evaluate topics in the emerging field of nanomaterials (i.e., distinguish progress

from hype, stimulate creative thinking).


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SUGGESTED READING MATERIAL

*Nanomaterials: Synthesis, Properties and Applications, ed. A. S. Edelstein and R. C.Cammarata, IoP (UK), 1996

*Handbook of Nanoscience, Engineering and Technology, ed. W.A.Goddard III, D.W.Brenner, S. E. Lyshevski, G.J. Iafrate, CRC Press, 2007Fundamentals of Microfabrication, M. J. Madou, Second Edition, CRC Press, 2002.Silicon VLSI Technology: Fundamentals, Practice, and Modeling by James D. Plummer,

Michael D. Deal, and Peter B. Griffin (Hardcover - Jul 14, 2000)Nano/Microscale heat transfer by Z.M. Zhang, McGraw-Hill, 2007

Reference Books

Articles

M.A. Meyers, A. Mishra, D.J. Benson, Mechanical properties of nanocrystallinematerials, Progress in Materials Science 51 (2006) 427556

Additional readings will be assigned with the lectures and uploaded on the classwebpage.

* Books on Reserve in the SFL library


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INTRODUCTION


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INTRODUCTION: Where did it all start?

http://www.zyvex.com/nanotech/feynman.html

There is Plenty of Room at the BottomRichard Feynman, December 29th 1959, APS Meeting

What I want to talk about is the problem of manipulating andcontrolling things on a small scale. As soon as I mention this, people tell me about miniaturization,and how far it has progressed today. They tell me about electric

motors that are the size of the nail on your small finger. And there

is a device on the market, they tell me, by which you can write theLord's Prayer on the head of a pin. But that's nothing; that's themost primitive, halting step in the direction I intend to discuss. It isa staggeringly small world that is below. In the year 2000, whenthey look back at this age, they will wonder why it was not until

the year 1960 that anybody began seriously to move in thisdirection.Why cannot we write the entire 24 volumes of the Encyclopedia

Brittanica on the head of a pin?


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Caltech, BS (1932)

The three scientists received the Nobel Prize in 1956

M.C. Hersam, 2005


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Founder and co-founder and Chairman Emeritus of Intel Corporation,Caltech, PhD (1954)


The first planarintegrated circuit, 1960.Designed and built byLionel Kattner and IsyHaas under the directionof Jay Last at FairchildSemiconductor


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M.C. Hersam, 2005


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M.C. Hersam, 2005


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Nanostructures in nature

Magnetotactic bacteria

Ferritin (protein complex for intracellular

iron storage)

Molluscal teeth, Gecko feet(H. A. Lowenstam, Science 27 July 1962: Vol. 137. no.

3526, pp. 279 280)

Afarensis, FCD

SCHRODL, MICHAEL y GRAU, JOS H.

Rev. chil. hist. nat. , 2006, 79,1,3-12.

http://www.metridium.com


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Nanostructures in history

Late Roman, 4th century ADThis extraordinary cup is the only complete example of a very special type of glass, known as dichroic, which changes

colour when held up to the light. The opaque green cup turns to a glowing translucent red when light is shone through it.The glass contains tiny amounts of colloidal gold and silver, which give it these unusual optical properties.

The British Museum


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INTRODUCTION: Definitions


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INTRODUCTION: Definitions

Nanotechnology

NanoStructureS

NanoStructureD

NanoTools

NanoDevices

Fullerenes Nanotubes Nanowires Nanofibers

Nanoparticles Quantum Dots

Nanoscaledmicrostructures

in bulk or thin films Nanograins Nanocrystalline

materials Nanocomposites

FabricationTechniques

Analysis andMetrology

Software forNanotech

Electronic MEMS/NEMS Biodevices/Lab-on-a-chip Biosensors

Drug delivery/Therapeutics

Data Storage Catalysis

Nanoscaledmachines

NanoSystems


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Something about NanostructureS


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INTRODUCTION: Panoramic view of NanostructureS

CARBON BASEDNANOSTRUCTURES:

-Fullerenes- Carbon Nanotubes

- Graphene

Wikimedia Commons


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INTRODUCTION: Panoramic view of NanostructureS: Carbon 1/3

1) BUCKYBALLS (Fullerene)

C60 Molecule (1985):by R.E. Smalley, R.F. Curl and H.W. Kroto

Nobel Prize 1996.

Graduate Students:James Heath and Sean OBrien

RELEVANCE:It was a new form of Carbon, besidesgraphite, diamond and amorphous

www.nanotech-now.com


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2) Carbon Nanotubes

Single sheet of graphite rolled upby Sumio Iijima of NEC in 1991

(though origin of discovery is debated)

RELEVANCE: Another new form of Carbon, has

excellent mechanical, thermal andchemical properties.Wikimedia Commons


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3) Graphene is a single planar sheet of sp-bondedcarbon atoms. Graphenes are the 2-Dcounterparts of 3-D graphite

A new rising star, The NYT titles:Thin Carbon Is In: Graphene StealsNanotubes Allure April 10th, 2007

RELEVANCE:Electrons behave as if they had no mass(2D electron gasses)

Room T quantum Hall effect

NYT


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NANOPARTICLES

Particles with size


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INTRODUCTION: Panoramic view of NanostructureS: Nanoparticles 3/3

QUANTUM DOTS

2 nm 6 nm

is a semiconductor nanostructure that confines themotion of conduction band electrons, valence bandholes, or excitons (bound pairs of conduction bandelectrons and valence band holes) in all three spatialdirections.

RELEVANCE:

Have superior transport andoptical properties.

Used in diode lasers, labelingand optical sensors.

Image of fluorescence in various sized CdSe Q.D.sDr. D. Talapin, University of Hamburg

Y. Galperin, 2007


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INTRODUCTION: Panoramic view of NanostructureS: Nanowires

NANOWIRESstructures that have a lateral sizeconstrained to tens of nanometers or lessand an unconstrained longitudinal size. Atthese scales, quantum mechanicaleffects are important hence such wiresare also known as "quantum wires ".

RELEVANCE:Have new electrical properties.Proposed for computing, solar

cells and metamaterials

TYPES: metallic (e.g., Ni, Pt, Au), semiconducting (e.g., Si, InP, GaN. ..), insulating (e.g., SiO2,TiO2), molecular nanowires are composed ofrepeating molecular units either organic(e.g. DNA) or inorganic.

GaN NIST nanowires that emit ultraviolet light


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INTRODUCTION: Panoramic view of NanostructureS: Nanofibers

NANOFIBERS

Nanofibers are defined as fibers withdiameters less than 100 nanometers.

They can be produced by interfacialpolymerization and electrospinning.

RELEVANCE:

Low density, large surface area tomass, high pore volume, and tightpore size make the nanofiber nonwoven appropriate for a widerange of applications from medical toto high-tech and aerospace,capacitors, transistors, drug deliverysystems, battery separators, energystorage, fuel cells, and informationtechnology

Nordson.com


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INTRODUCTION: Why is nanoscale special?

M.C. Hersam, 2005

M.J. Biggs


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INTRODUCTION: Why is nanoscale special? - INTERFACES

M.J. Biggs


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INTRODUCTION: Why is nanoscale special? QUANTUM EFFECTS

The Heisenberg uncertainty principle gives alower bound on the product of the standarddeviations of position and momentum for a

system, implying that it is impossible to have aparticle that has an arbitrarily well-definedposition and momentum simultaneously.

M.J. Biggs


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INTRODUCTION: Why is nanoscale special? - THERMAL

Thermal fluctuations can be commensurate withthe size of nano-systems, making their designand use very difficult (they influence, forexample, the rates of chemical reactions anderror rates in nanomechanical systems).

One example:For very small ferromagnetic (FM) particles the magnetic

anisotropy energy (responsible for keeping the magnetizationoriented in certain directions) is comparable to the thermalenergy (kT). When this happens, the particles becomesuperparamagnetic ; as thermal fluctuations randomly flip themagnetization direction between parallel and antiparallelorientations. b, When the ferromagnetic nanoparticle is placedclose to an antiferromagnetic (Anti-FM) surface the exchangebias interaction at the FM/Anti-FM interface provides additionalanisotropy energy, which stabilizes the magnetization in onedirection and prevents superparamagnetism.

J. Eisenmenger and I.K. Schuller, Magneticnanostructures: Overcoming thermal fluctuations,

Nature Materials 2, 437 - 438 (2003)


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M.C. Hersam, 2005

INTRODUCTION: Why is nanoscale special? - THERMAL


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INTRODUCTION: Why is nanoscale special? - DISCRETENESS

M.J. Biggs


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2) Nanoscaled microstructures in bulk or thin films they are single or multi-phase polycrystals with nanoscale (1x10-9 250x10-9 m) grain size.

INTRODUCTION: Panoramic view of NanostructureD Materials

Nanocrystalline NiTi, TEM bright field image.Europhys. Lett., 71 (1), p. 98 (2005)

Uniformultrafinegrainstructure

2-Phaseultrafinegrainstructure Dispersion of nanoscaled

precipitatesProgress in Materials Science 51 (2006) 427-556


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INTRODUCTION: Why is nanoscale special?

Properties of Nanostructured Materials:

Mechanics:

- Elasticity changes (E, G as grain size )

- Mechanical Strength ( as grain size ) [Hall-Petch or Inverse Hall Petch?]

0=lattice friction, ky = HP slope, d=grain size

- Ductility:in metals as grain size in ceramics fracture toughness

Ductile Brittle Transition

Diffusion

Magnetic

Thermal and Electrical conductivity

21

0

+= d k y y

Progress in Materials Science 51 (2006) 427-556


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INTRODUCTION: NANOTOOLS

New Physics in the Numerical, Theoretical and Experimental techniquesto Process and Study nanomaterials

Synthesis techniques for nanostructures and nanostructured materials:

- TOP DOWN

- BOTTOM UP

New and old experimental methods devised for their testing and characterization

- Electron Scattering techniques- Force based techniques

- MEMS and in-situ testing

Numerical methods and multiscale modeling

a b

c

d

SiSiO 2

Resist

Negative Resist Positive Resist

EtchingEtching

Mask

Light Sourcea b

c

d

SiSiO 2

Resist

Negative Resist Positive Resist

EtchingEtching

Mask

Light Source


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INTRODUCTION: NANODEVICES

New Physics in the Numerical, Theoretical and Experimental techniquesto Process and Study nanomaterials

Electronic

MEMS/NEMS Biodevices/

Lab-on-a-chip

Biosensors

Drug delivery/

Therapeutics

Data Storage

Catalysis Nanoscaled machines

Reed/Yale

www.mse.umd.edu

Copyright 1999 David Morgan-Mar


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INTRODUCTION: NNI

The National Nanotechnology Initiative (NNI) [http://www.nano.gov/]

Reed/Yale


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INTRODUCTION: NNI

The National NanotechnologyInitiative (NNI)

[http://www.nano.gov/]

lecture 1 why is nano-scale special

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