M. Meyyappan
Director, Center for Nanotechnology
NASA Ames Research Center
Moffett Field, CA 94035
email: meyya@orbit.arc.nasa.gov
web: http://www.ipt.arc.nasa.gov
Nanotechnology deals with the creation of USEFUL
materials, devices and systems through control of matter on
the nanometer length scale and exploitation of NOVEL
phenomena and properties (physical, chemical, biological)
at that length scale
Nanometer
• One billionth (10-9) of a
meter
• Hydrogen atom 0.04 nm
Proteins ~ 1-20 nm
Feature size of computer
chips 180 nm
Diameter of human hair
~ 10 µm
• Examples
- Carbon Nanotubes
- Proteins, DNA
- Single electron transistors
• Not just size reduction but phenomena
intrinsic to nanoscale
- Size confinement
- Dominance of interfacial phenomena
- Quantum mechanics
• New behavior at nanoscale is not
necessarily predictable from what we
know at macroscales.
AFM Image of DNA
• Atoms and molecules are generally less than a nm and we study
them in chemistry. Condensed matter physics deals with solids
with infinite array of bound atoms. Nanoscience deals with the
in-between meso-world
• Quantum chemistry does not apply (although fundamental laws
hold) and the systems are not large enough for classical laws of
physics
• Size-dependent properties
• Surface to volume ratio
A 3 nm iron particle has 50% atoms on the surface
A 10 nm particle
20% on the surface
A 30 nm particle
only 5% on the surface
• Many existing technologies already depend on nanscale materials
and processes
- photography, catalysts are “old” examples
- developed empirically decades ago
• In existing technologies using nanomaterials/processes, role of
nanoscale phenomena not understood until recently; serendipitous
discoveries
- with understanding comes opportunities for improvement
• Ability to design more complex systems in the future is ahead
- designer material that is hard and strong but low weight
- self-healing materials
•
1959 Feynman Lecture “There is Plenty of Room at the
Bottom” provided the vision of exciting new discoveries if
one could fabricate materials/devices at the atomic/molecular
scale.
•
Emergence of instruments in the 1980s; STM, AFM providing
the “eyes”, “fingers” for nanoscale manipulation,
measurement…
•
STM
Image of Highly Oriented
Pyrolitic Graphite
Recently, there has been an explosion of research
on the nanoscale behavior
- Nanostructures through sub-micron self
assembly creating entities from “bottom-up”
instead of “top-down”
- Characterization and applications
- Highly sophisticated computer simulations to
enhance understanding as well as create
‘designer materials’
•
For information, www.nano.gov
•
Multiagency Initiative in nanotechnology starting in FY01 “National Nanotechnology
Initiative (NNI)
- Leading to the Next Industrial Revolution”
•
FY03 Nano budget is $679 M, representing 17%
•
Biggest portion of the funding goes to NSF
- Followed by DoD, NASA, DOE, NIH
- All these agencies spend most of their nano funding on university programs
•
Very strong activities in Japan, Europe, China, Singapore, fueled by Government Initiatives
•
Nano activities in U.S. companies: IBM, Motorola, HP, Lucent, Hitachi USA, Corning,
DOW, 3M…
- In-house R & D
- Funding ventures
•
Nano Centers being established at Universities all across the world
•
Emerging small companies
- VC funding on the increase
•
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The U.S. does not dominate
nanotechnology research. Nearly twice
as much ongoing research overseas as
in the U.S. In 1997 Govt. expenditures
on Nanotechnology Research: U.S.:
$118 M, Japan: $120 M, Europe:
$122 M, Others: $65 M.
Many foreign leaders, companies,
scientists believe that nanotechnology
will be the leading technology of the
21st century. The fact that there is still
a chance to get on the ground floor
explains pervasive R & D worldwide.
Strong nanotechnology programs in
Singapore, Australia, Korea, Taiwan,
China and Russia.
Leadership Position
Synthesis & Assembly
U.S.
Europe
Biological Approaches
& Application
U.S./Eur
Japan
Dispersions and
Coatings
U.S./Eur
Japan
High Surface
Area Materials
U.S.
Europe
Japan
Nanodevices
Japan
Europe
U.S.
Level
1
2
Japan
3
Highest
Source: WTEC Report
•
Academia will play key role in development of nanoscience and technology
- Promote interdisciplinary work involving multiple departments
- Develop new educational programs
- Technology transfer to industry
•
Government Labs will conduct mission oriented nanotechnology research
- Provide large scale facilities and infrastructure for nanotechnology research
- Technology transfer to industry
•
Government Funding Agencies will provide research funding to academia, small business, and
industry through the NNI and other programs (SBIR, STIR, ATP…)
•
Industry will invest only when products are within 3-5 years
- Maintain in-house research, sponsor precompetitive research
- Sponsor technology start-ups and spin-offs
•
Venture Capital Community will identify ideas with market potential and help to launch start-ups
•
Professional societies should establish interdisciplinary forum for exchange of information; reach
out to international community; offer continuing education courses
Before taking the bread and butter courses, the undergraduate training begins with:
NOW
SHOULD WE CONSIDER?
•
Should elective courses on nanotechnology be considered (one or two)? If so, coverage
includes, but not limited to:
- Bulk vs. nano properties
- Introduction to synthesis and characterization
- Examples of nanomaterials: tubes, wires, particles…
- Surface phenomena
- Quantum phenomena
- Focus on emerging applications
- ?
•
Summer internship and/or academic year co-op
- National labs
- Small and large companies with nano programs
- University research
•
Degree in Nanotechnology?
- Flinders University and University of New South Wales in Australia now offer B. Sc.
in Nanoscience and Technology
- Leeds University and Crane University in U.K. offer M. Sc. in Nanoscience and
Technology
- This, of course, has to be a university-wide effort with courses taught by Physical
and Biological Sciences and Engineering Departments
“The emerging fields of nanoscience and nanoengineering are leading to
unprecedented understanding and control over the fundamental building blocks of
all physical things. This is likely to change the way almost everything - from
vaccines to computers to automobile tires to objects not yet imagined - is
designed and made.”
- from IWGN Report
Societal and Economic Benefits
- Materials and Manufacturing
- Nanoelectronics and Computing
- Medicine and Health
- Environment and Energy
- Transportation
- National Security
- Aeronautics, Space exploration
“As we enter the 21st century,
nanotechnology will have a major impact
on the health, wealth and security of the
world’s people that will be at least as
significant in this century as antibiotics,
the integrated circuit, and man-made
polymers.”
- from IWGN Report
Organic
Inorganic
Nanoelectronics
Sensors,
NEMS
Bio
Structural
Applications
Materials
Applications
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•
•
•
•
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Nanocrystalline materials
Nanoparticles
Nanocapsules
Nanoporous materials
Nanofibers
Nanowires
Fullerenes
•
•
•
•
•
•
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Nanotubes
Nanosprings
Nanobelts
Dendrimers
Molecular electronics
Quantum dots
NEMS, Nanofluidies
As Recommended by the IWGN Panel
•
Nanostructure Properties
- Biological, chemical, electronic, magnetic, optical, structural…
•
Synthesis and Processing
- Enable atomic and molecular control of material building blocks
- Bioinspired, multifunctional, adaptive structures
- Affordability at commercial levels
•
Characterization and manipulation
- New experimental tools to measure, control
- New standards of measurement
•
Modeling and simulation
•
Device and System Concepts
- Stimulate innovative applications to new technologies
1. What novel quantum properties will be enabled by nanostructures (at room temp.)?
2. How different from bulk behavior?
3. What are the surface reconstructions and rearrangements of atoms in nanocrystals?
4. Can carbon nanotubes of specified length and helicity be synthesized as pure
species? Heterojunctions in 1-D?
5. What new insights can we gain about polymer, biological…systems from the
capability to examine single-molecule properties?
6. How can one use parallel self-assembly techniques to control relative arrangements
of nanoscale components according to predesigned sequence?
7. Are there processes leading to economic preparation of nanostructures with control
of size, shape… for applications?
•
Ability to synthesize nanoscale building blocks with control on size,
composition etc.
further assembling into larger structures with
designed properties will revolutionize materials manufacturing
- Manufacturing metals, ceramics, polymers, etc. at exact shapes without
machining
- Lighter, stronger and programmable materials
- Lower failure rates and reduced life-cycle costs
- Bio-inspired materials
- Multifunctional, adaptive materials
- Self-healing materials
• Challenges ahead
- Synthesis, large scale processing
- Making useful, viable composites
- Multiscale models with predictive capability
- Analytical instrumentation
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Carbon Nanotubes
Nanostructured Polymers
Optical fiber performs through sol-gel
processing of nanoparticles
Nanoparticles in imaging systems
Nanostructured coatings
Ceramic Nanoparticles for netshapes
Source: IWGN Report
• Nanostructured metals, ceramics at exact shapes without machining
• Improved color printing through better inks and dyes with
nanoparticles
• Membranes and filters
• Coatings and paints (nanoparticles)
• Abrasives (using nanoparticles)
• Lubricants
• Composites (high strength, light weight)
• Catalysts
• Insulators
‘Self-healing plastic’ by Prof. Scott White (U. of Illinois)
Feb. 15, 2001, Issue of Nature
• Plastic components break because of mechanical or thermal
fatigue. Small cracks  large cracks  catastrophic failure.
‘Self-healing’ is a way of repairing these cracks without human
intervention.
• Self-healing plastics have small capsules that release a healing
agent when a crack forms. The agent travels to the crack
through capillaries similar to blood flow to a wound.
• Polymerization is initiated when the agent comes into contact
with a catalyst embedded in the plastic. The chemical reaction
forms a polymer to repair the broken edges of the plastic. New
bond is complete in an hour at room temperature.
Past
Shared computing
thousands of
people sharing a mainframe computer
Present
Personal computing
Future
Ubiquitous computing
thousands of computers sharing each
and everyone of us; computers embedded in walls, chairs, clothing,
light switches, cars….; characterized by the connection of things in
the world with computation.
“There is at least as far to go (on a logarithmic scale) from the present as
we have come from ENIAC. The end of CMOS scaling represents both
opportunity and danger.”
-Stan Williams, HP
•
4-8 CMOS generations left but cost of building fabs going up faster than
sales. Physics has room for 109x current technology based on 1 Watt
dissipation, 1018 ops/sec
no clear ways to do it!
- Molecular nanoelectronics
- Quantum cellular automata
- Chemically synthesized circuits
•
Self assembly to reduce manufacturing costs, defect tolerant architectures
are critical to future nanoelectronics
• Quantum Computing
- Takes advantage of quantum mechanics
instead of being limited by it
- Digital bit stores info. in the form of ‘0’ and
‘1’; qubit may be in a superposition state of
‘0’ and ‘1’ representing both values
simultaneously until a measurement is made
- A sequence of N digital bits can represent
one number between 0 and 2N-1; N qubits
can represent all 2N numbers simultaneously
1938
1998
Technology engine:
Vacuum tube
Technology engine:
CMOS FET
Proposed improvement:
Solid state switch
Proposed improvement:
Quantum state switch
Fundamental research:
Materials purity
Fundamental research:
Materials size/shape
- Stan Williams
•
Carbon nanotube transistor by IBM and
Delft University
•
Molecular electronics: Fabrication of logic gates
from molecular switches using rotaxane
molecules
•
Defect tolerant architecture, TERAMAC computer
by HP
architectural solution to the
problem of defects in future molecular electronics
• Processors with declining energy use and cost per gate, thus
increasing efficiency of computer by 106
• Higher transmission frequencies and more efficient utilization of
optical spectrum to provide at least 10 times the bandwidth now
• Small mass storage devices: multi-tera bit levels
• Integrated nanosensors: collecting, processing and
communicating massive amounts of data with minimal size,
weight, and power consumption
• Quantum computing
• Display technologies
•
Expanding ability to characterize genetic makeup will
revolutionize the specificity of diagnostics and
therapeutics
- Nanodevices can make gene sequencing more
efficient
•
Effective and less expensive health care using remote
and in-vivo devices
• New formulations and routes for drug
delivery, optimal drug usage
Nanotube-based
biosensor for
cancer diagnostics
• More durable, rejection-resistant artificial
tissues and organs
• Sensors for early detection and prevention
• DNA microchip arrays using advances for IC industry
• ‘Gene gun’ that uses nanoparticles
to deliver genetic material to
target cells
• Semiconductor nanocrystals
as fluorescent biological labels
Source: IWGN Report
• Thermal barrier and wear resistant coatings
• High strength, light weight composites for increasing fuel
efficiency
• High temperature sensors for ‘under the hood’
• Improved displays
• Battery technology
• Automatic highways
• Wear-resistant tires
•
Nanotechnology has the potential to impact energy efficiency, storage and
production
•
Materials of construction sensing changing conditions and in response
altering their inner structure
•
Monitoring and remediation of environmental problems; curbing emissions;
development of environmental friendly processing technologies
•
Some recent examples:
- Crystalline materials as catalyst support, $300 b/year
- Ordered mesoporous material by Mobil oil to remove ultrafine
contaminants
- Nano-particle reinforced polymers to replace metals in automobiles to
reduce gasoline consumption
Some critical defense applications of nanotechnology include
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Continued information dominance: collection, transmission,
and protection
High performance, high strength, light weight
military platforms while reducing failure rates and
life cycle costs
Chemical/biological/nuclear sensors; homeland protection
Nano and micromechanical devices for control of
nuclear and other defense systems
Virtual reality systems based on nanoelectronics for
effective training
Increased use of automation and robotics
• Advanced miniaturization, a key thrust area to enable new science and
exploration missions
- Ultrasmall sensors, power sources, communication, navigation,
and propulsion systems with very low mass, volume and power
consumption are needed
• Revolutions in electronics and computing will allow reconfigurable,
autonomous, “thinking” spacecraft
• Nanotechnology presents a whole new spectrum of opportunities to build
device components and systems for entirely new space architectures
- Networks of ultrasmall probes on planetary surfaces
- Micro-rovers that drive, hop, fly, and burrow
- Collection of microspacecraft making a variety of measurements
• Lots of nanoscience, little nanotechnology
• Short term (< 5 years)
- CNT based displays
- Nanoparticles
* Automotive industry (body moldings,
timing belts, engine covers…)
* Packaging industry
- CNT-based probes in semiconductor metrology
- Coatings
- Tools
- Catalysts (extension of existing market)
• Medium term (5-15 years)
- Memory devices
- Fuel cells, batteries
- Biosensors (CNT, molecular, qD based)
- Advances in gene sequencing
- Advances in lighting
• Long term (> 15 years)
- Nanoelectronics (CNT)
- Molecular electronics
- Routine use of new composites in Aerospace,
automotive (risk-averse industries)
Red Herring, May 2002
Commonality: Railroad, auto, computer, nanotech
all are enabling technologies
Source: Nanoscale Materials in Chemistry, Wiley, 2001
The melting point decreases dramatically as the particle
size gets below 5 nm
Source: Nanoscale Materials in Chemistry, Wiley, 2001
• For semiconductors such as ZnO, CdS, and Si, the bandgap
changes with size
- Bandgap is the energy needed to promote an electron
from the valence band to the conduction band
- When the bandgaps lie in the visible spectrum, changing
bandgap with size means a change in color
• For magnetic materials such as Fe, Co, Ni, Fe3O4, etc., magnetic
properties are size dependent
- The ‘coercive force’ (or magnetic memory) needed to
reverse an internal magnetic field within the particle is
size dependent
- The strength of a particle’s internal magnetic field can be
size dependent
• Zeolite is an old example which has been around a long time and
used by petroleum industry as catalysts
• The surface area of a solid increases when it becomes nanoporous;
this improves catalyst effects, adsorption properties
• ‘Adsorption’ is like ‘absorption’ except the absorbed material is
held near the surface rather than inside
• How to make nanopores?
- lithography followed by etching
- ion beam etching/milling
- electrochemical techniques
- sol-gel techniques