NANO SCIENCE & ENGINEERING IN MECHANICS by Ken P. Chong PhD, - - PowerPoint PPT Presentation

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NANO SCIENCE & ENGINEERING IN MECHANICS

by

Ken P. Chong

PhD, PE, Hon. M.ASCE, F.AAM

Director of Mechanics & Materials Program National Science Foundation www.nsf.gov

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creation of new materials, devices and systems at the molecular level phenomena associated w/ atomic & molecular interactions strongly influence macrospic mat’l properties [I. Aksay, Princeton] significantly improved mechanical, optical, chemical, electrical... properties “there is plenty of room at the bottom”

[Richard Feynman, 1959]

“nanoscale technology will have an impact equal to the Industrial Revolution”

[Rita Colwell, 2002]

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1 nm ~ 5 atoms length ductile ceramics [w/ grain size in low nm range] fireflies convert chemical energy to light w/ near-perfect efficiency [ ME, Nov. ‘00] nano-photosynthesis: green technology MEMs as platform for NEMS bio-nanotechnology

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• M. ROCO, ~2002

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Organizations that have prepared and contribute to the National Nanotechnology Initiative (NNI)

Office of Science and Technology Policy (OSTP) National Science and Technology Council (NSTC)

White House Departments

DOC/NIST, DOD, DOE, DOJ, DOS, DOT, DOTreas, DHS, USDA IWGN (October 1998-August 2000) NSET (August 2000 - continuing)

Independent Agencies

EPA, FDA, NASA, NIH, NRC, NSF, USG

Federal Government R&D funding NNI (~$700M in 02) Industry (private sectors) ~ NNI funding State and local (universities, foundations) ~ 1/2 NNI funding Est.:

M.C. Roco, NSF, 5/29/03

Office of Management and Budget (OMB) Presidential Council of Advisors in Science and Technology (PCAST)

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Nanoscale Science and Engineering support at NSF in FY 2004

The budget allocation expected between $249M (NSF Request) and $350M (Congress bills)

• Program solicitations (about $91M, about 1/3)

Nanoscale Science and Engineering - $79M, NSF 03-043 Nanoscale Science and Engineering Education - $12M, NSF 03-044

• Support in the core program (about 2/3) with focus on single

investigator & other core Various research and education programs in all directorates Interdisciplinary fellowships; STC, MRSEC and ERC centers Instrumentation (REG, MRI); Collaboration industry (GOALI, PFI); Network for Computational Nanotechnology ($2.8M/yr); National Nanotechnology Infrastructure Network ($14M/yr); Nanoscale Informal Science and Education (NSF 03-511)

• SBIR/STTR (additional ~ $10M)

M.Roco, NSF, 9/29/03

Fundamental nanoscale science and eng’g - Principal Areas of Investigation – core programs (FY 2002)

• Biosystems at the Nanoscale

~ 14%

biostructures, mimicry, bio-chips

• Nanostructure ‘by Design’, Novel Phenomena 45%

physical, biological, electronic, optical, magnetic

• Device and System Architecture

20%

interconnect, system integration, pathways

• Environmental Processes

6 %

filtering, absorption, low energy, low waste

• Multiscale and Multiphenomena Modeling

9 %

• Manufacturing at the nanoscale

6%

• Education and Social Implications (distributed)

M.C. Roco, NSF, 01/31/03

Grand Challenges (NNI, FY 2002)

• Nanostructured materials "by design"

~ 22%

• Nanoelectronics, optoelectronics and magnetics 39%
• Advanced healthcare, therapeutics, diagnostics 8%
• Environmental improvement

4%

• Efficient energy conversion and storage

5%

• Microcraft space exploration and industrialization

3%

• CBRE Protection and Detection (revised in 2002) 7%
• Instrumentation and metrology

6%

• Manufacturing processes

5%

(details in the NNI Implementation Plan, http://nano.gov)

M.C. Roco, NSF, 01/31/03

National Science Foundation

NSF - a pioneer among Federal agencies

and at the international level in Nanoscale Science and Engineering (NSE)

FY 2003: ~ 1/3 of Federal and 1/10 of World Investment – Seven themes: Biotechnology, Nanostructures ‘by design’ and novel phenomena, Device and system architecture, Environmental Processes, Multiscale modeling, Nanoscale manufacturing; Societal implications and Improving human performance – Establishing the infrastructure: over 1,600 active projects; 20 large centers, 2 user facilities (NNIN, NCN), multidisciplinary teams – Training and education over 7,000 students and teachers

Fiscal Year NSF HR766 2000 $97M 2001 $150M 2002 $199M 2003 $221M R 2004 $249M $350M

50 100 150 200 250 300 350 2000 2001 2002 2003 2004 R NSE ($M)

• Congr. Bill

M.C. Roco, 10/09/03

Nanotechnology R&D Funding by Agency

Fiscal year 2000 2001 2002 2003 2004 (all in million $)

Enacted/actual Enacted/actual Requests

National Science Foundation 97 150 /150 199 / 204 221 249 Department of Defense 70 110 /125 180 /180 243 222 Department of Energy 58 93 /88 91.1 /89 133 197 National Institutes of Health 32 39 /39.6 40.8 /59 65 70 NASA 5 20 /22/ 35 /35 33 31 NIST 8 10 /33.4 37.6 /77 69 62 Environmental Protection Agency

• /5.8

5 /6 6 5 Homeland Security (TSA)

• 2 /2

2 2 Department of Agriculture - /1.5 1.5 /0 1 10 Department of Justice - /1.4 1.4 /1 1.4 1.4 TOTAL 270.0 422.0 /464.7 ~ 600 /653 ~ 774 ~ 849 Other NNI participants are: OSTP, NSTC, OMB, DOC, DOS, DOTreas, FDA, NRC, DHS, Intel

M.C. Roco, NSF, 2/20/03

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BASIC INSTRUMENTS & TOOLS

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Principle of AFM

SEM image of the AFM cantilever and tip. http://www.di.com/app_notes/spmtechnology_appnotes.htm MEASURE FORCE F = F(d)

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• LIMITATIONS

AFM SCAN SPEED ~100HZ [TAKES ~30 MIN. FOR A SMALL IMAGE OF 20,000 PIXELS]

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NEMS Nano-photosynthesis Cyberinfrastructure

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LDLM Large Deformation Laser Moire FGLM Fine Grating Laser Moire LSI Laser Speckle Interferometry DIC Digital Image Correlation HRTEM High Resolution Transmission Electron Microscopy CFTM Computational Fourier Transform Moire AFM Atomic Force Microscopy SEM Scanning Electron Microscopy SRES Surface Roughness Evolution Spectroscopy

Map of Deformation-Measurement Techniques

I n t e r f a c e E n e r g y L i m i t I n t e r f e r

• m

e t r i c G a i n

• f

R e s

• l

u t i

• n

H R T E M

• C

F T M LDLM DIC S R E S F G L M & L S I Field Projection Method Equilibrium Smoothing

Field of View (Gage Length in ) m Strain Resolution

10

• 1

10

• 9

10

• 8

10

• 7

10

• 6

10

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10

• 2

10

• 3

10

• 4

10

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10

• 6

A F M I n t e r f e r

• m

e t r y NSF Award No. CMS-0070057, Engineering Directorate (Program Manager: Dr. K.P. Chong & Jorn Larsen-Basse) K.-S. Kim, Nano & Micromechanics Laboratory, Brown University

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• L. SUNG, NIST

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Van der Waals Force

www.topometrix.com/spmguide/1-2-0.htm

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EDUCATION

• 10-12 m

QUANTUM MECHANICS [TB, DFT, HF…]

• 10-9

MOLECULAR DYN. [LJ…]; NANOMECHANICS; MOLECULAR BIOLOGY; BIOPHYSICS

• 10-6

ELASTICITY; PLASTICITY; DISLOCATION...

• 10-3

MECHANICS OF MATERIALS

• 10-0

STRUCTURAL ANALYSIS

MULTI-SCALE ANALYSES & SIMULATIONS… ____________________________________________________________

TB = TIGHT BINDING METHOD; DFT = DENSITY FTNAL THEORY; HF = HATREE-FOCK APPROX.; LJ = LENNARD JONES POTENTIAL

• NSF SUMMER INSTITUTE OF NANOMECHANICS & MAT’LS, NORTHWESTERN UNIVERSITY –

contact: PROF. W.K. LIU

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CHALLENGES multi-scale

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BORESI AND CHONG, ELASTICITY IN ENGINEERING MECHANICS, WILEY, 2000.

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Qualitative Predictions Quantitative Predictions

Structural Mechanics Molecular Assembly Computational Chemistry

Computational Materials

Computational Mechanics

• Electrons
• Nuclei
• Atoms
• Molecular fragments
• Bond angles
• Force Fields
• Surface Interactions
• Orientation
• Crystal Packing
• Molecular Weight
• Free Volume
• Constituents
• Interphase
• Damage

Fiber Matrix

Length, (m)

10-12 10-9 10-6 10-3 100

Nano Meso Quantum Micro

NASA Langley Research Center Nanotechnology Modeling and Simulation

Macro

C C C CO CO CO CO2 CO2 CO2 CO

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Multi Multi-

• Scale Multi

Scale Multi-

• Phenomena Modeling of

Phenomena Modeling of Structure / Property / Structure / Property / Function Function

10 µm

Multi-Scale Composite Epoxy Matrix

Nanocomposite 1 µm

Carbon Fiber

Nanocomposite

Carbon Fiber

100 nm

Carbon Nanotubes

1 nm

Zig-Zag Armchair

Atomic Interactions

r0

θ

1 Å

Modeling Hierarchy – Bridging the Scale from Nano to Macro

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Modeling and Measuring the Structure and Properties of Cement-Based Materials

http://ciks.cbt.nist.gov/monograph/

Over 10,000 users from 83 countries per month

MODEL

nm nm

• m

m mm mm

REAL

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Atomistic Modeling of the Contact Problem

Repulsive potential indenter: Findenter ~ (R-r)2 for r<R

R r

Fixed B.C. Fixed B.C. Fixed B.C. Free surface Free surface

ˆ y ˆ z ˆ x

EAM constitutive law:

Ecoh = Gi

i

∑ ρj

a Rij

( )

i≠ j

∑       + 1 2 Uij

i, j j≠i

( )

∑ Rij

( )

ˆ y ˆ x ˆ z

• E. T. Lilleodden,
• J. Zimmerman,
• S. Foiles and W.D. Nix

William D. Nix, Stanford University

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Atomistic Calculation of Indentation Response

50 100 150 2 4 6 8 10

S

Sneddon’s analysis

• f Unloading Curve:

Hertz’s loading equation:

Depth (Å) Load (nN)

168,000 atoms, (001) surface of Au indented P = 4 / 3

( )E* Rh3/2

E*=89 GPa E* = S π 2 A = 90GPa

• E. T. Lilleodden,
• J. Zimmerman,
• S. Foiles and W.D. Nix

William D. Nix, Stanford University The MD calculations mirror the experiments; here displacement bursts result in a load drop rather than a displacement excursion because the MD calculations represent a “hard testing” machine. The elastic responses are correctly modeled.

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RAJIV KALIA, LSU

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DISCUSSIONS OF COMMON MODELING METHODS

• FIRST PRINCIPLE CALCULATIONS - TO SOLVE

SCHRODINGER’S EQ. AB INITIO, e.g. HATREE- FOCK APPROX., DENSITY FUNCTIONAL THEORY,…

• COMPUTIONAL INTENSIVE, O(N4)
• UP TO ~ 3000 ATOMS
• MOLECULAR DYNAMICS [MD] - DETERMINISTIC, e.g. W/

LENNARD JONES POTENTIAL

• MILLIONS TIMESTEPS OF INTEGRATION; TEDIOUS
• UP TO ~ BILLION ATOMS FOR NANO-SECONDS
• COMBINED MD & CONTINUUM MECHANICS [CM], e.g.

MAAD; LSU; BRIDGING SCALE; …

• PROMISING...

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CNTs

National Science Foundation CARBON NANOTUBES [CNT]

• honeycomb lattices of carbon rolled into

cylinders; nm in diameter, micron in length

• 1/6 the wt. of steel; 5 times E; 100 times

tensile strength; 6 orders of magnitude higher in electrical conductivity than copper; MWNT strains up to 15%

• 10 times smaller than the smallest

silicon tips in STM [CNT is the world’s smallest manipulator]

• CNT may have more impact than

transisters

• ideal mat’l for flat-screen TV [~2003]

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• self-assemble in deposition from C-rich

vapors

• similar diameter as DNA
• bridge different scales in mesoscale - useful

as bldg. blocks ~ e.g. nanocomposites;gases storage

• metallic or semiconducting
• as single-electron transistor; logic gate
• as RAM - on/off do not affect memory storage
• no booting needed

CARBON NANOTUBES -THE FIRST 10 YEARS, NATURE, 2001. MECHANICAL ENGINEERING, ASME, NOV. 2000 TECHNOLOGY REVIEW, MIT, MAR. 2002

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Diameter and helicity are characterized by (n, m) Electronic properties depend on (n, m), exhibiting metallic or semiconducting behavior

• Figs. by Yong Zhu/Rod Ruoff, Northwestern U.

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MOLECULAR STRUCTURAL MECHANICS APPROACH

Computational Chemistry Molecular Molecular Structural Structural Mechanics Mechanics Computational Mechanics Computational Chemistry Molecular Molecular Structural Structural Mechanics Mechanics Computational Mechanics

Merging of Chemistry and Mechanics

Bond Beam Nanotube Space Frame

T.-W. Chou, U. DE

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N N L M M L

θ

T T L

r0

Structural Mechanics Molecular Mechanics CORRESPONDING RELATION OF PARAMETERS

τ

=k L GJ

θ

=k L EI

r

k L EA =

Li and Chou, International Journal of Solids and Structures (2003) Li and Chou, Physical Review B (2003)

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LINKAGE BETWEEN COMPUTATIONAL STRUCTURAL MECHANICS AND COMPUTATIONAL CHEMISTRY

• Energy conservation principle is universal
• Structural mechanics can be established based on

strain energy theory

• Computational chemistry is based on steric potential

energy theory (molecular force field)

• Energy equivalence can be used to provide a link

between computational structural mechanics and computational chemistry

T.-W. Chou, U. DE

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BUCKLING PRESSURE OF SWNT

0.5 1.0 1.5 2.0 2 4 6 8 10 12 Nanotube diameter (nm) Buckling pressure (GPa)

Experiment(Tang et al.) ab initio (Reich et al.) Experiment(Chesnokov et al.) Zigzag Armchair

Li and Chou, Physical Review B (2004), Li and Chou, Mechanics of Materials (2004)

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OTTO ZHOU, UNC-CH ~15% strain

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MULTI – SCALE HYBRID COMPOSITES: BRIDGING THE MICRO AND NANO SCALES

1 mm 500 nm 1 µm 5 nm 5 nm

Thostenson et al., Journal of Applied Physics (2002) Thostenson and Chou, Journal of Physics D: Applied Physics (2003)

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10 100 1000 1 10 100 0.1

Specific Modulus GPa/(g/c3) Specific Strength, GPa/(g/c3)

0.2 0.5 2 5 20 50 20 50 200 500

Aluminum 2219

Baseline Material, available today Best available under development

CFRP Composite

Properties of Carbon Properties of Carbon Nanotubes Nanotubes (CNT) (CNT)

CNTFRP Composite Single Crystal bulk material (CNT)

Emerging material, carbon nanotubes

Long-term potential

• f CNT material

from NASA-larc

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MIT

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sensors, smart, bio, nano materials …

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• C. ROGERS

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Artificial NOSE – Operation principle

Eight cantilevers functionalized with eight different polymers or blends

H.P. Lang, M.K. Baller, Ch. Gerbe

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NIST 2 m Integrating Sphere

Simulated Photodegradation

via

High Energy Radiant Exposure

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Integrating Sphere Technology

Characteristics of Integrating Sphere Output:

• Uniform diffuse radiation
• Constant radiance and irradiance at exit port.
• Constant irradiance between exit ports

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Polymeric Materials Requiring UV Exposure

• Coatings
• Textiles
• Vinyl Siding
• Bulk Plastics
• Asphalt *
• Roofing membranes/shingles
• Sealants *
• Geotextiles *
• Fiber-reinforced composites *

* Load bearing

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Polymer Nanocomposites NIST

• Flame retardant materials
• Conducting polymers
• Scratch resistant coatings
• Self-healing materials
• Self-disinfecting surfaces…

C a r b

• n

N a n

• t

u b e s SiO2 ZnO TiO2 L a y e r e d S i l i c a t e s Polyethylene E p

• x

y Polypropylene Polystyrene PDMS Nylon P M M A P

• l

y u r e t h a n e T P O A g Nanowires Q u a n t u m D

• t

s

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Nano-Clay Filled Polymers NIST

Si O Al, Mg OH

• Certain types of clay naturally form platelet

structures – Thickness just less than 1 nm – High aspect ratios

• Lengths and widths are 25 to 2000

times the thickness – Gallery spacing between platelets between 1.5 nm and 2 nm

• Contain cations for charge balance

– Hold platelets together

• Use of just 1% to 5% by volume can

dramatically alter material behavior – Properties related to flammability improved – Mechanical properties improved – Improvements often depend on ability to separate and disperse platelets

• Organic treatment needs to be

thermally stable.

~ 1 nm

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Metal Oxide Nanoparticles in Coatings

• TiO2 and ZnO used in nanosize forms

in sunscreens – Photoreactive behavior

• Good absorbers of UV light
• Deactivate and destroy:

– Bacteria, viruses, fungi – Organic and inorganic pollutants in air and water – Cancer cells

• Producing energy via

photoelectrochemical cells

• Applications include:

– “Self-disinfecting” surfaces – Paints and coatings with improved durability – Indoor air cleaners – Water treatment – Mitigation of air-borne biological agents – Solar cells

CB VB

hυ

H2O H2O H2O O2 O2 O2 O2

hole + electron –

If charge carriers get to surface: O2

• superoxide

OH.

hydroxyl radical

H2O2

hydrogen peroxide and other activated oxygen species can be generated. All are capable of further reaction with

• rganic materials for good or bad

NIST

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www.nsf.gov

Chong, K. P., “Research and Challenges in Nanomechanics” 90- minute Nanotechnology Webcast, ASME, Oct. 2002; archived in www.asme.org/nanowebcast NSF SUMMER INSTITUTE ON NANO MECHANICS & MATERIALS http://tam.northwestern.edu/summerin stitute/Home.htm

National Science Foundation NSF Summer Institute on Nano Mechanics and Materials*

Co-sponsored by Northwestern University, American Society of Mechanical Engineering, NASA URETI BIMat Center, Northwestern University Materials Research Center, NU Nanoscale Science and Engineering Center, Northwestern University, CSET, NSF IGERT on virtual tribology and AVS Science & Technology Society.

Professor Wing Kam Liu (Director) Professor Ted Belytschko (Co-Director) Professor Yip Wah Chung (Co-Director) *Funded by the Civil and Mechanical Systems Division, monitored and guided by Dr. Ken P. Chong, Prog. Director.

National Science Foundation Defining the vision and implementation plan Defining the vision and implementation plan

National Nanotechnology Initiative National Nanotechnology Initiative Reports Reports

Planning with feedback after each: 5 years, 1 year, 1 month; and various levels: national/NSET, agency, program In preparation: Topical reports; new 2004:10 year vision

1999: 10-year vision

• MC. Roco, 10/09/03

Worldwide benchmark Brochure for public Societal implications Govt plan

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SUMMARY & DISCLAIMER An overview of major advances, challenges and research concerning mechanics and materials are presented. The author would like to thank his colleagues and many members of the research communities for their comments and input during the writing of this presentation. Information on NSF initiatives, announcements and awards can be found in the NSF website: www.nsf.gov. The opinions expressed in this article are the author’s only, not necessarily those of the National Science Foundation [NSF]

• r NIST. Any commercial products identified are

for illustrations only, do not imply any endorsement.

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Questions/comments?