1/22/2016
Nanotechnology, the Rise of Super
Materials, and the Acceleration of
Engineering Technology
Dr. Bob Welch
Consultant
IEEE Mississippi Section Meeting
Mississippi College, Clinton, MS
21 January 2016
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Nanotechnology’s Beginnings – Richard Feynman’s
talk “Plenty of Room at the Bottom”
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Credited as starting field of Nanotechnology.
Presented to American Physical Society Meeting
at Cal Tech (29 December 1959).
Purpose was to create interest in research at
small scale (of order nanometers).
Provided examples of specific opportunities at
small scales within the Laws of Physics.
Feynman later won the Noble Prize in Physics
(1965, Quantum Electrodynamics).
Feynman later served on Presidential
Commission on Challenger Disaster (1986) and
provided explanation of failure (o-ring cold
temperature response).
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
Feynman’s example of “PLENTY Of ROOM”
at the Bottom – How could we do better with
data storage?
Microfilm was the state of the art for printed media
storage in 1959.
• Provided ~1/400 reduction in size.
• Used in many libraries of the time.
• Provided method to archive newspapers, books,
journals, etc.
*
Microfilm
Reader
Microfilm
Feynman’s question: “Within physical laws,
how small a volume can we store the
information in books?”
* "Microfiche reader and source code" by Autopilot - Own work. Licensed under CC BY-SA 3.0 via Commons https://commons.wikimedia.org/wiki/File:Microfiche_reader_and_source_code.jpg#/media/File:Microfiche_reader_and_source_code.jpg
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
Feynman’s example – “Plenty of room at the bottom” printed media storage
Consider books in major libraries of the world in 1959:
• 1 Library of Congress~9 million books
• 1 British Museum Library~5 million books
• 1 National Library of France~5 million books
• Some are duplicates, so guess 24 million books in the world in 1959.
How small of a space could we store this information?
• Assume each book ~ volume of Encyclopedia Britannica2 (1000 pages, 1300
words/page, 7 characters/word) produces 2.2 x 1014 characters for all books.
• Assume 7 bits to define each character & 125 atoms to represent each bit
(cube 5 X 5 X 5 atoms): for Carbon (diamond) atoms, Volume ~ 4.6 x 10-28 m3).
• Then all books could be written in volume ~ 7.1 x 10-13 m3.
0.2
• Head of a pin volume ~ 3.5 x 10-10 m3 (about 500 times as big!).
mm
1.5 mm
THERE’S PLENTY OF ROOM AT THE BOTTOM!
1 Today
2 New
these libraries contain ~ 40 million books (about 2X).
York Times, 8 Feb 1994.
Head of Straight Pin
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
There is so much room at the Bottom
that…
Every cell of every animal and every plant on Earth
contains a copy of the organism’s entire blueprint.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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What is Nanoscale and Nanotechnology?
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Nanotechnology is science, engineering, and
technology conducted at the nanoscale, which is
about 1 to 100 nanometers.
One nanometer is a billionth of a meter, or 10-9 of a
meter.
There are 25,400,000 nanometers in an inch.
A sheet of newspaper is about 100,000 nanometers thick
A human hair is approximately 80,000- 100,000
nanometers wide
The distance between 2 carbon atoms in a diamond
lattice is about 0.15 nanometers.
A strand of human DNA is 2.5 nanometers in diameter
Your fingernail grows about 1 nanometers/second.
Matter often exhibits different properties at the nanoscale
than at larger scales.
Scale of Things
(from NNI Website)
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
National Nanotechnology Initiative (NNI)
The NNI:
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Proposed by Dr. Mihail Rocco in 1999 brief to the White House.
Mission: Improve fundamental understanding and control of matter
at the nanoscale & translate that into solutions for national needs.
Was inaugurated by President Clinton in 2000.
Was renewed by both Republican and Democratic administrations.
Has major impact on U.S.’s technological competitiveness.
Is a Federal R&D initiative involving 20 Federal departments.
Is overseen by the Nanoscale Science, Engineering, and
Technology (NSET) Subcommittee.
Is coordinated by the National Nanotechnology Coordinating Office.
Had 2015 expenditures of about $1.5 B.
Provided the U.S. with an early lead in nanotechnology.
Dr. Mihail Rocco
NSF Senior Advisor on
Nanotechnology
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
US Army Engineer Research and
Development Center (ERDC)
(Research Laboratories of
the Corps of Engineers)
Laboratories
Field Offices
Cold Regions Research
Engineering Laboratory
(Hanover, NH)
Topographic
Engineering Center
(Alexandria, VA)
Construction Engineering
Research Laboratory
(Champaign, IL)
ERDC Statistics
Headquarters (Vicksburg, MS)
Coastal & Hydraulics Laboratory
~ $1.1 Billion annual budget
Environmental Laboratory
Geotechnical & Structures Laboratory
~ 2500 employees
Information Technology Laboratory
Over 1020 engineers & scientists
32% have PhDs
45% have MS degrees
Facilities include 18th most powerful super computing resources (3.3 Petaflops/s)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Civil and Military Engineering can be considered
as 3 areas:
• Classical and Continuum Mechanics – fairly static.
• Policies and procedures – slowly changing.
• Materials – potential orders-of-magnitude
improvement
– Requires design at the molecular level (atomistic
simulations).
– Requires building to molecular design.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
Micro-Scale Versus
Macro-Scale Strength
Micro-scale samples of material can be
extremely strong (e.g., iron whiskers ~
1.9 million psi tensile strength).
As the sample size increases, defects
within molecules, weak bonds between
molecules, and voids significantly
weaken the material.
Macroscopic materials typically have only
2% to 5% of the strength of the micromaterials (e.g. bulk iron ~ 30 ksi to 50
ksi).
Intelligent design at the molecular level is
necessary to understand and
overcome/minimize these weaknesses.
Tensile Strength of Whiskers
(After S.S. Brenner, 1956)
Material
Diameter
(X 10-6 m)
Tensile
Strength
Iron
1.60
13.1 GPa
Copper
1.25
2.93 GPa
Silver
3.80
1.72 GPa
Tensile Strength of Iron Whiskers
Verus Sample Diameter
(After S.S. Brenner, 1956)
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Tensile Strength - GPa
9
Iron Whisker
Data
5
4
3
High Strength Steel
(200 KSI)
2
1
0
0
0.1 0.2 0.3 0.4 0.5
1/Diameter - (1/microns)
0.6
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
Silicon Carbide
(Ivashchenko, et. al., 2007)
ERDC Materials Research from
Nanoscale to Macroscale
Carbon Nanotube Bundle
(Cornwell, et. al., 2009)
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Past improvements in structural materials were based largely on trial and error, were evolutionary
and not revolutionary, and made improvements usually of a few 10’s of percent or less.
ERDC adopted a different approach in ~ 2005 to speed up the process and to attempt to develop
“super” engineering materials, i.e., those with many times improved strength/mass and
stiffness/mass ratios over existing materials.
The new approach took the view that to achieve many-fold improvements in materials
strengths/stiffness, we’d have to operate at the molecular level, and use the strongest/stiffest
molecules available.
ERDC Advanced Material Initiative (AMI) employed:
– Atomistic and multiscale simulations to guide material design.
– Carbon nanotubes (CNTs), graphene, silicon carbide, and other “super” molecules and
crystalline structures as strength members.
– Multiscale material response and diagnostics to validate simulations.
– Advanced material synthesis guided by atomistic and larger-scale simulations.
Much of the technology supporting this approach is being developed as it is being used (e.g.,
nanoscale material response, atomistic & multi-scale simulations).
Design first, then build (at the molecular level).
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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ERDC Advanced Materials Initiative - Research Team
ERDC Researchers:
Dr. Bob Ebeling (Team Lead-Structural Concepts), Dr. Charles Marsh (Team Lead-Material
Synthesis), Dr. Charles Cornwell (Team Lead – Atomistic Modeling), Dr. Mei Chandler, Toney
Cummins, Dr. Paul Allison, Richard Haskins, Dusty Majure, Clint Arnett, Dr. N. Jabari Lee,
Dr. James Baylot, Dr. Bryce Devine, Dr. Fran Hill, Thomas Carlson, Dr. Kevin Abraham, Pete
Stynoski, Thomas Hymal, Jonathan George, Ben Ulmen, Dr. Meredith C.K. Sellers, Kyle Ford,
Erik Wotring, Mr. Wayne Hodo, Dr. Jeff Allen, Dr. Laura Walizer, Dr. John Peters (Co-Lead), Dr.
Bob Welch (Lead, Co-Lead).
Collaborators with ERDC:
US Army Natick: Claudia Quigley, Karen Buehler, Dr. Mike Sennett.
NASA: Dr. Richard Jaffe (NASA Ames), Dr. Mike Meador (NASA Glenn)
Rice U.: Prof. Matteo Pasquali, Nobel Laureate Robert Curl, Prof. Robert Hauge
Colorado School of Mines: Prof. David T. Wu
DTRA: Dr. Jeffrey DePriest, Dr. Heather Meeks
MIT/ISN: Prof. Mike Strano, Prof. Markus Buehler
U. of Illinois/Champaign: Prof. P. Mondal, Prof. W. Kriven, Prof. A.Bezryadin
ARL: Dr. D.Papas, Dr. M. Fleischman, Dr. J.Campbell, B.Klotz, E. Klier
ARO MURI Team: Dr. D. Stepp, Dr. D. Kiserow, Prof. H.Espinosa, Prof. G. Schatz, others
Imperial College/Queen Mary College/Oxford U: Prof. Eduardo Saiz, Prof. Mike Reece, Prof.
Nicole Grobert, Prof. Richard Todd (funded/coordinated through Army International Research
Office, Dr. Russell Harmon).
DoD HPCMO PETTT-funded: Prof. Susan Sinnott (U. FL); Prof. Steve Stuart (Clemson U.);
Prof. Anthony Rollett (Carnegie Mellon U.)
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
Initial Super Materials Program:
Carbon Nanotube-Based Filaments
ERDC Molecular Dynamics
simulation of a HCP bundle of
carbon nanotubes (Cornwell, 2007)
Goal: Develop carbon nanotube (CNT)-based 1-million-psi (7 GPa) tensile material
(filaments, membranes) to Technology Readiness Level 4 (lab demo).
This would be a major accomplishment:
 Results in material with 2X strength/weight ratio of Kevlar and 5X tensile strength of
very high strength steel (4340 alloy).
 Inaugurates a paradigm shift in material development.
 Lays the technical foundation accelerate development of other “super” materials and
materials by design.
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
 ij 
1E6
1E3
Newtonian Mechanics
Tight Binding MD
Quantum Mechanics
Density Function Theory
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Atomistic Simulation Based
Material Studies
Atom Count
FEM
Molecular Dynamics
1 E
V  ij
Hartree-Fock
Quantum Mechanics: Schrodinger Equation
Pico
Nano
Micro
Milli
Time Span (seconds)
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Past material studies were mostly empirical (recall Hook’s Law, late 1600’s).
– Empirical studies use laboratory tests (e.g., unconfined compressive strength,
tensile tests, etc.) to understand response and design material.
– These provide little insight on molecular-level phenomena where mechanical
response begins.
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Atomistic-based simulations use forces between atoms and molecules to
predict mechanical behavior.
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Require enormous computing power.
Have been practical only within the last 20 years (still developing).
Can predict mechanical properties before material is fabricated.
Allow trade studies to be made:
• Molecular defects versus strength, stiffness.
• Molecule-molecule bonding versus strength, stiffness.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
Carbon Nanotubes
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Received global attention as a result of 1991 “discovery” article by Iijima and others
(actually discovered several times earlier, see Monthioux & Kuznetsov, Carbon 44, pp
1621, 2006).
Carbon nanotubes (and graphene) are the strongest molecules ever discovered
(Dresselhaus et al., 2004).
CNTs are essentially graphene rolled into a tube.
Tensile strength of ~110 GPa (15.5 million psi, 150 X high-strength steel).
Density 1/6 to 1/3 that of steel (multiwall versus single-wall).
Young’s modulus 1 TPa (150 million psi, 5 x that of steel).
Strength/Weight Ratio – 450X to 900X steel.
Quality, quantity, production breakthroughs have occurred frequently.
From 2006 to 2011, global production increased by over a factor of 10 (De Volder, et
al., Science, 1Feb2013)
Currently used in batteries, plastics, water filters, auto parts (e.g., fuel lines - electrical
conduction), very high end sporting goods (Easton Sports).
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Effects of Molecular Defects on
CNT Tensile Strength
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Eqvide.mpg
Tight Binding Molecular
Dynamics simulations of (5,5)
carbon nanotubes
Eqvide.mpg
CNTs display amazing strength and stiffness even with
defects.
Most carbon nanotubes suffer brittle failure at room
temperature.
Simulation results were substantiated in Peng et al., 2008.
(Welch et al., 2006; Haskins et al., 2007)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
What About Molecule to Molecule Bonding?
(van der Waals Forces and Critical Length)
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van der Waals forces cause attraction
between central CNT and surrounding
molecules (force/unit length).
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We wanted to determine “critical overlap
length” that would provide molecular
bonding as strong as the CNT’s.
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Filaments composed of CNTs of ~ twice
the critical length would presumably be as
strong as the carbon nanotubes.
Hexagonal closest
packed array of
CNTs
DLPOLY_3 simulation of interaction of carbon
nanotubes chirality (5,5) (Majure, et al.)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Molecular Dynamics Simulations
Effects of CNT Length on CNT Fiber Response
Gaussian Distributions
of CNT Lengths
Fiber Tensile Response
F_2000_3000_100.1.avi
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Fiber Tensile Strength VS CNT Length
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All fibers were 2000Å long.
Constituent CNTs were 300, 500, and 700Å
average length.
Over a million atoms were used in simulations.
NO CRITICAL LENGTH!
(Cornwell et al., 2009)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Interstitial Carbon Atom Bonding
Between CNTS - Preliminary Results
 Experimentalists report interstitial carbon atom-CNT bonds created via
irradiation (e.g., Kis et al., 2004; Peng et al., 2008).
 Interstitial carbon atom-CNT bonds are several orders of magnitude
stronger than van der Waals forces.
(5,5) 7-CNT Bundle Vs. Interstitial Sheer Test
2.00E+001
Force (eV/A)
1.50E+001
1.00E+001
(5,5)
Interstitial
5.00E+000
0.00E+000
0
5
10
15
20
25
-5.00E+000
Displacement (Angstrom)
Interstitial carbon atom-CNT bond versus
van der Waals (Majure et al., 2008)
Interstitial-test.mpg
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
Million PSI, Scalable CNT Fiber Design (Cross-Linked Fibers)
CNT Fiber with cross-links
Sample.wmv
~ 8.6 Million PSI
Goal –
1 Million PSI
Cross-link densities varied from 0.125 % to 0.75%
(Cornwell and Welch., 2011, 2012)
Simulations were perhaps the first to identify a scalable molecular
design, and predict mechanical properties, for a many-million-psi fiber.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Molecular Dynamics CNT-Interlinked Fiber
Brittle-Ductile Behavior Study (2012)
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Study showed fibers would go from ductile to
brittle behavior as the interlink density
increased.
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Ultimate tensile strength decreased with
increased ductility.
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Provides design guidance on fine-tuning fiber
radiation treatment.
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Only chirality (5,5) considered.
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Chirality (5,5) displays brittle behavior (unless
pre-twisted).
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Stress-strain curves for fibers
of different interlink densities.
Does not consider fiber twist.
Cornwell and Welch, Molecular
Simulations, 12 April, 2012.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Synthesizing CNTs
Modified Ferrocene Catalytic Chemical Vapor
Deposition (CCVD)
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ERDC started with minimal expertise in 2007.
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ERDC adopted the CCVD method and further
refined it to produce taller CNT forest
(temperature, feed stock/carrier gas ratio,
sonicator, etc.).
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ERDC ultimately grew CNT forests to 3.5 mm,
possibly the record within the DoD.
ERDC 3.5-mm-tall CNT forest
Uniform CNT
forest growth in
quartz tube
Ferrocene CCVD Chamber
Barriero et al., J. Phys. Chem. B, 110, 2006
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Building the CNT Fiber
Some ERDC Contributions to CNT Material Synthesis
Discovery of CNT Forest
Growth Termination
Mechanism
(with MIT/ISN)
Microbiology directed
ssDNA Ligation of CNTs
(Arnett et al., Langmuir,
2010), Patent Pending
384,000 PSI
CNT Fiber
(with MIT/ISN)
CCVD Synthesis
Refinements
(3.5-mm CNT
Forests, possibly
DoD Record)
Self-Assembled Tube Structure
(SATS) Discovery
ERDC Cover Article
Marsh et al., Carbon, May 2011.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com 23
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Structural Impact of Super Materials
Whisker of thousands of multiwall carbon
nanotubes (Marsh et al., 2008)
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Structural impact of “super materials” can be are non-intuitive.
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Suppose a CNT fiber paint could be produced that had 40% of the tensile strength of
(5,5) carbon nanotubes (40% CNT strength = 44 GPa or 6.2 million psi).
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If 0.005-inch thickness of this paint was applied to a ½-inch thick, 60,000 PSI steel
plate:
– The paint would have the same tensile load capabilities as the steel plate.
– The paint would be a significant structural component.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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2nd Material Project – Ultra-Lightweight “Super” Structural Ceramic
Silicon Carbide “Almost Great”
Structural Material
Civil Infrastructure and Buildings
Super CNT/Graphene
Silicon Carbide Composite
Silicon Carbide “Almost Great” Material
• Mass produced from abundant materials (Si, C)
• High temp (3000 deg F) and corrosion resistant
• 6X stiffness/weight ratio of steel or aluminum
• 17X comp. strength/weight of 100-KSI steel
• 7X comp. strength/weight of high-strength alum.
• Weakness – low fracture toughness and tensile
strength (same as concrete)
•~2/3’s weight reduction for steel and alum.
•From abundant materials
•Probable high-temp, non-corrosive
Transportation Systems
Long Term Goal – Super SiC Composite
• Tensile strength and toughness improved to 5X
Risk: Not impossible, but very challenging goals.
• Senior researcher: “Not in my lifetime.”
Pay Off: About 2/3’s weight reduction for alum.
/steel structures & equipment .
Silicon Carbide Compared To HP Steel and Aluminum
Rational Design- Polycrystalline Material
• Empirical development of material design and
synthesis has reached an endpoint.
• Atomistic and larger scale simulations, coupled
with experiments, provide insight in material design
and synthesis, and will lead to rapid improvements .
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ERDC MD simulation of
Silicon Carbide
undergoing sintering
(Devine et al., 2011)
CNT/Graphene SiC Composite
“Super Ceramic”
ERDC Whisker of CNTs
(Marsh et al., 2007)
CNT/Graphene-SiC Composite Development Approach:
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Use silicon carbide as matrix/compressive member (boron carbide 2nd choice).
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Employ carbon nanotubes (CNTS), graphene, or SiC fiber and possibly hierarchical
structures to enhance tensile strength/fracture toughness*.
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Composite would be composed of silicon and carbon, abundant materials.
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Material design is similar to steel-reinforced concrete but at molecular scale.
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Use atomistic & larger scale simulations to guide both material design and synthesis.
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Validate simulations against nanoscale and macro-scale experiments.
* Experimentalists reported 25% to 75% improvement in SiC and aluminum oxide toughness via inclusion of CNTs
(e.g., Xai et al., 2004; Wang, 2006; Karandikar, 2007; Yamamoto, 2008.)
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Bonded CNTs
(Cornwell, 2008)
Silicon carbide
(Wikipedia)
“Super Ceramic”
(Silicon Carbide Composite)
Performance goals for CNT/graphene-SiC composite are (5X tensile strength/toughness):
• Density of ~175 lbs/ft3 – same as aluminum.
• Min. Young’s modulus ~ 30 million psi – same as steel.
• Min. compressive/tensile strength ~ 300,000 psi.
• *Min. fracture toughness – 25 MPa m1/2 - same as aluminum.
Given the above, the CNT/graphene-SiC composite would have:
• 3X stiffness-to-weight ratio of aluminum or steel.
• 4X strength-to-weight ratio of high-strength aluminum (e.g., 7075-T6).
• 9X strength-to-weight ratio of high-strength steel (100-ksi steel).
CNT/graphene SiC composite would be made of carbon and silicon, abundant materials.
Excluding costs, the most common structural design constraint is either maximum load
or maximum deflection (e.g., bridge has to carry a certain load; aircraft wing can only be
allowed to deflect so far).
Given these constraints, CNT/graphene-SiC could result minimum 66% weight reduction
in steel, and over 40% weight reduction in aluminum structures/equipment.
*Extremely difficult to achieve. One ceramic researcher response: “not in my lifetime.”
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
Simulations of Fracture in Nano-Crystalline 4H-SiC
(B. Devine, 2011)
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ERDC MD Simulations (4H-SiC) 20 nm
crystals, 10 million atoms.
~200,000 CPU Hours, 4-day turnaround on HPC Machines.
Columnar supercell of 20nm crystals
viewed along the [1120] direction.
Crystals are variously rotated around
the [1120] axis. Stress is applied in the
(1000) plane.
Normal atoms are invisible for clarity.
Black atoms are under-coordinated at
grain boundaries and surfaces.
Tan atoms are in a distorted crystal
orientation (HCP instead of FCC).
SiC Inter-crystalline failure confirmed
by experiment (P. Allison, 2011).

1120
6fps.wmv
Stress
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Molecular Dynamics Methods Development
CNT Fiber - Ceramic Matrix Interaction
Control Parameters
1. Crystallographic orientation of the grain
2. Fiber length and orientation (azimuthal & polar)
3. Fiber crosslink concentration (CNT-CNT & CNT-matrix)
4. Fiber average CNT length and standard deviation
(C. Cornwell, 2012)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
MD Simulations of Sintering
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System sizes up to 20 million atoms allows for
simulations of 32 nanocrystals with a mean diameter
of 20 nm (experimental size) ~ 200,000 cpu-hour
simulations; 4-day compute cycle (2000 processors)
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Simulation times of >10 ns. Sufficient to reach
intermediate stage behavior.
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Enables determination of:
► Early and intermediate stage consolidation
mechanisms.
► Effects of temperature, grain size, and time on
consolidation.
► Effect of crystal rotation on the intermediate
stage microstructure.
► Can we influence the microstructure and
porosity with control of the particle orientation,
size and size distribution?
MD Simulations of SiC Sintering
(Devine et. al., 2011, 2012)
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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ERDC Macro Modeling of Synthesis (Sintering)
of Polycrystalline Silicon Carbide (SiC)
Continuum simulations – Predict
temperatures, pressures, electric, and
magnetic fields within sintering chamber.
Continuum Simulations of SPS
(Allen et. al., 2011b)
Kinetic Monte Carlo (KMC) simulations –
Predict later-time sintering phenomena such
as full consolidation, non-symmetric grain
growth.
ERDC KMC Sintering Simulations
(Allen et. al., 2011b)
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Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
National and Global Trends In
Nanotechnology and Computational
Material Development
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Case Study: Molecular Dynamics and
Carbon Nanotube Materials – Are Other
Countries Using This Approach ?
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ERDC relies heavily on Molecular Dynamics in its carbon nanotube and other
material research.
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Search on key words “carbon nanotubes” returned 107,174 articles:
– Most prolific country – US – 25,590 articles (24%)
– 2nd most - China – 24,744 articles (23%)
– 3rd most – Japan – 9,413 articles (9%)
– 38% of articles published since 2012.
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Search on “carbon nanotubes” and “molecular dynamics” returned 5002 articles:
– Most prolific country - US – 1,683 articles (34%)
– 2nd most - China – 1,173 articles (23%)
Key word searches
– 3rd most – Japan – 401 articles (8%)
performed 20 Jan 2016 and
used the technical data base
– 33% of articles published since 2012.
Elsevier Scopus.
Worldwide, other researchers are taking similar approaches.
~ 1/3 research occurred within last 4 years.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Growth in High Performance Computing Capability
Impact on Computation Materials Research
•
World-wide High Performance Computing (HPC)
resources are continuing to evolve into faster platforms.
•
ERDC typical large Molecular Dynamic (MD) simulations
used about 0.2 million CPU-hours (4-day compute, ~
2000 processors).
•
More powerful computers will allow larger/faster
exploration of material design space, more complex
materials, more accurate MD potential functions, and
larger material volumes.
Some Supercomputers
at ERDC1
TOPAZ – 4.62 PFLOPS
•
DARPA’s Exascale Computing Project (1000X
improvement in computing speed), if it were successful,
would change a 4-day compute cycle to a 6-minute
compute cycle.
•
Current predictions are that Exascale (1000 PFLOPS)
Super Computers will not be available until sometime in
the 2020s because of required improvements in energy
efficiency.2
Garnet – 1.5 PFLOPS
1
ERDC DSRC computers listed
as 18th most powerful globally
(November 2015 TOP500)
2
IEEE Spectrum, Jan. 2016
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
White House Announcement – 24 June 2011
President’s Materials Genome Initiative (MGI)
“The lengthy time frame for materials to move from discovery to market is due in part to the
continued reliance of materials research and development programs on scientific intuition and trial
and error experimentation…. Some of these experiments could potentially be performed virtually
with powerful and accurate computational tools…”
•
•
•
•
MGI’s goal is to accelerate US material development to
increase US global competitiveness.
MGI is developing a “Materials Innovation Infrastructure”
which includes integrated computational, experimental, and
informatics tools, as a key to accelerating material
development.
There is close coordination between the MGI and the
National Nanotechnology Initiative (NNI).
Both the MGI and the NNI are managed by staffers from the
White House Office of Science and Technology Policy (Dr.
Cyrus Wadia and Dr. Lloyd Whitman).
ERDC’s Advanced Materials Initiative produced an early example
of using atomistic and larger-scale computations to accelerate
the design of advanced materials (super fiber, super ceramic).
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Engineering and Nanotechnology
We’ve reached the conclusion that many (most?) things that engineers care
about are strongly influenced by phenomena at the nanoscale, for example:
Some macroengineering areas affected or
controlled by nanoscale phenomena:
–
–
–
–
–
–
–
–
–
–
–
Macromaterial strength & stiffness
Macromaterial synthesis
Friction
Combustion and detonation
Lubricants/coatings performance
Heat transmission
Fluid-structure interaction
Photovoltaics
Corrosion, weathering, aging
Ice formation and adherence
Electrical and magnetic material
properties
– Cellular and subcellular behavior
– Life (as pointed out by Feynman in 1959).
ERDC Articles
ASCE Magazine
November 2008
Carbon
May 2011
Nanotechnology is the new frontier
for civil and military engineering
technology advancement.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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1/22/2016
Summary
•
Nanotechnology enables the accelerated development of many areas of engineering
technology (e.g., structural materials, improved fluid-structure interaction, improved
combustion, lubricants, etc.) by providing insight on the nanoscale phenomena which
influences or controls the technology.
•
The National Nanotechnology Initiative (NNI) gave the US an early start in
Nanotechnology.
•
Materials have largest potential for improvement (orders-of-magnitude) of the 3 areas
of Civil and Military engineering (mechanics, policies/procedures, materials).
•
ERDC’s Advanced Material Initiative (AMI) adopted a different approach to material
development from traditional macro-scale trial-and-error testing and analysis, to using
molecular and larger-scale simulations, validated by experiments, to guide both
material design and material synthesis (Design first, then build, at the
molecular/crystalline scale).
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Design first, then build (at the molecular/crystalline level).
Long Term Product
Silicon Carbide
Composite
Summary
•
ERDC’s AMI program made significant advances in several areas including:
– Material synthesis
– Using molecular and larger-scale simulations to guide material design and
synthesis
– Design of “super materials” (super fiber, super ceramic).
•
Other nations are beginning to take similar multi-scale simulation/experiment based
approaches to material development.
•
The President’s Material Genome Initiative (MGI) seeks to accelerate material
development via the use of molecular- and larger-scale simulations to guide material
design and material synthesis.
•
ERDC’s Advanced Material Initiative is an early example of success using the MGI
approach to develop materials with many-fold improvements in performance.
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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Design first, then build (at the molecular/crystalline level).
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1/22/2016
Thank You!
Nanotech, Super Materials, & Technology Acceleration - Dr. Bob Welch - charles.r.welch@gmail.com
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