Nanotechnology

S. Tom PicrauxDept. of Chemical and Materials Engineering

Fulton School of Engineeringpicraux@asu.edu

Arizona State University

Science, Technology and Public AffairsPAF 547

This presentation has 2 objectives:

- Overview the scientific basis of nanotechnology

- Highlight the government’s role and current public policy issues in nanotechnology

— working with matter down to the molecular level to create structures and devices ~1 to 100 nm in size with fundamentally new organization, properties, and performance

Nanotechnology: a definition

• takes us to the realm where the properties of materials are dramatically different.

• demands new tools and new understanding.

• may hold the key to a 21st century industrial revolution.

What are the key challenges of nanoscale science and technology?

Making nanomaterials Self assembly, top down vs. bottom up

Characterizing nanostructures Imaging and measuring small things

Understanding properties “Nanoland” lies between macro world and single atoms and molecules

Nanosystems integration & performance - How do we assemble nanostructures into systems (this is the high payoff area)

Self-Assembly: Nature’s approach to nanotechnology

Photosynthesis centers• optical receptor molecules are precisely

aligned via spontaneous organization• alignment promotes collection, storage,

and utilization of light energy

Living Cell Walls• “fluid” molecular arrays rearrange

in response to chemical stimuli• changes in membrane structure

influence intercellular diffusion

Dynamic restructuring of moleculararrays provides adaptive response.

3D molecular arrangementspromote resonant coupling.

How to build things at the nanoscale?Conventional MachinesBuild and assemble

Microelectronics Top down - build in place

NanotechnologyBottom up - self assembled

(m - mm)

(10 - 0.1 µm)

(1- 100 nm)

Things NaturalThings Natural Things ManmadeThings Manmade

Fly ash~ 10-20m

Head of a pin1-2 mm

Quantum corral of 48 iron atoms on copper surfacepositioned one at a time with an STM tip

Corral diameter 14 nm

Human hair~ 50-120m wide

Red blood cellswith white cell

~ 2-5 m

Ant~ 5 mm

Dust mite

200 m

ATP synthase Nanotube electrode

Carbon nanotube~1.3 nm diameter

O O

O

OO

O OO O OO OO

O

S

O

S

O

S

O

S

O

S

O

S

O

S

O

S

PO

O

The Challenge

Fabricate and combine nanoscale building blocks to make useful devices, e.g., a photosynthetic reaction center with integral semiconductor storage.

Mic

row

orl

d

0.1 nm

1 nanometer (nm)

0.01 m10 nm

0.1 m100 nm

1 micrometer (m)

0.01 mm10 m

0.1 mm100 m

1 millimeter (mm)

1 cm10 mm

10-2 m

10-3 m

10-4 m

10-5 m

10-6 m

10-7 m

10-8 m

10-9 m

10-10 m

Visi

ble

Nan

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1,000 nanometers = In

frar

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ltrav

iole

tM

icro

wav

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ft x-

ray

1,000,000 nanometers =

Zone plate x-ray “lens”Outer ring spacing ~35 nm

Office of Basic Energy SciencesOffice of Science, U.S. DOE

The Scale of Things – Nanometers and MoreThe Scale of Things – Nanometers and More

MicroElectroMechanical (MEMS) devices10 -100 m wide

Red blood cellsPollen grain

Carbon buckyball

~1 nm diameter

Self-assembled,Nature-inspired structureMany 10s of nm

Atoms of siliconspacing ~tenths of nm

~10 nm diameter

DNA~2-1/2 nm diameter

Nanomaterials: new physics and chemistry

revolutionizes materials performance

Lead to:GPa strength from Ni

New phenomena associated with:• Small size (e.g. quantized effects)

• Preponderance of surfaces and interfaces

• New modes of electronic transport

• Radical changes in collective phenomena

• New chemical reactivities

• New mechanical properties0

1

2

3

4

5

6

Al+O-impl. Ni

Type 440Cbearing steel

Ni

Yie

ld S

tren

gth 2-nm Al2O3

particles

Single moleculesensing

Practicing “alchemy” through structure

Carbon Nanotubes: example of extreme properties

Nanotubes for Electronics, Scientific American, Dec. 2000

The scale of nanostructures

Top down

(~200 nm)

Bottom up

(~1 nm)

armchair

zig-zag

Information technology Quantum electronics (logic, memory), magnetic memory, spintronicsEnergy Large scale, low cost nanoparticle-based solar energy collection High efficiency solid state lightingHealth In situ drug delivery Diagnostics, active monitoring, performance enhancementEnvironment Low cost, nanosensor arrays for health, safety Nanoparticle based waste destruction Nanomanufacturing Large area, bottom up assembly for low waste, energy efficient manufacturing

Why are nanomaterials attractive?

Practical applications are at an early stage

The Top Ten Nanotech Products Of 2003 Robert Paull, The Forbes/Wolfe Nanotech Report, 12/29/03

1) High-Performance Ski Wax 2) Breathable Waterproof Ski Jacket 3) Wrinkle-Resistant, Stain-Repellent Threads 4) Deep-Penetrating Skin Cream 5) World's First OLED Digital Camera 6) Nanotech DVD and Book Collection   7) Performance Sunglasses 8) Nanocrystalline Sunscreen 9 & 10) High-Tech Tennis Rackets And Balls

It has been estimated that nanostructured materials and processes can be expected to have a market impact of over $340 billion within a decade (Hitachi Research Institute, 2001).

Public visibility is growing

Washington Post, Sunday, Feb. 22, 2004

Nanotechnology and SocietyNanotechnology and Society

• Are paradigm shifting consequences of nanotechnology likely to occur?

• Are there areas where broad societal debate needs to be carried out concurrent with research?

• What is the role of government?

• What are the responsibilities of scientists and engineers?

0100200300400500600700800900

1000

FY01 FY02 FY03 FY04 FY05 (req)

Pre-programFY01 funding

Total NNI

Funding($M)

Fiscal Year

National Nanotechnology Initiative U.S. Funding

Worldwide nanotech funding ~$3.5B in FY03: (Europe, Japan, US, Korea, Singapore, Taiwan, China, …)

Governments play a significant role in the development of Nanotech

0

50

100

150

200

250

300

350

NSF DOD DOE NIH NIST NASA EPA Others

FY04 Funding by Agency

NNI Funding

($M)

Nanotechnology cuts across a wide area of society

U.S. Government Agency

NNI Program Grand Challenges

1. Nanostructured materials by design 2. Manufacturing at the nanoscale3. Chemical-biological-radiological-explosive detection4. Nanoscale instrumentation and metrology5. Nano-electronics, photonics, and magnetics6. Healthcare, therapeutics and diagnostics7. Efficient energy conversion and storage8. Microcraft and robotics 9. Nanoscale processes for environmental improvement

The enormous U.S. investment in nanotechnology is predicated on economic competitiveness and societal

impact

S189 signed Dec. 3, 2003National Nanotechnology Bill

An authorization bill Follows the NNI program directions Emphasizes program:

management coordination review/oversight and ethical, legal, environmental and societal concerns!

Governments respond to societal priorities and concerns

The National Nanotechnology Bill creates:

American Nanotechnology Preparedness Center 1) “conduct, coordinate, collect, and disseminate studies on the societal, ethical,

environmental, educational, legal and workforce implications of nanotechnology”

2) “identify anticipated issues related to the responsible research, development, and application of nanotechnology, as well as provide recommendations for preventing or addressing such issues”

Center for Nanomaterials Manufacturing1) encourage, conduct, …. research on new manufacturing technologies for

materials, devices, and systems …2) Develop mechanisms to transfer such manufacturing technologies to U.S.

industries

Specific societal-driven inclusions in the S189 Bill

Nanotechnology and Society:

Nanoparticles – Potential Health Risks

• Properties change with size.− Can some sizes + compositions have adverse health effects?

− Implications for gov’t regulatory system.Same chemical, different forms: e.g., carbon black, diamond, buckyball, nanotube

Same chemical, different size: e.g. TiO2, quantum dots (CdS, CdSe)

• Can nanoscale particles cross biological barriers?

• What are our responsibilities and precautions?− in the lab?

− in the factory or the environment?

− in consumer products?

Nanoscale Materials Categorizations

Naturally occurring “ultrafine particles” Virus – 10 to 60 nm Bacteria – 30 to 10 µm Dust from deserts - ~ 100 nm Volcanic ash, Forest fire smoke

“Ultrafine particles” from established technologies or by products of conventional Processes

Combustion soot – 10 to 80 nm Paint pigments – 80 to 100 nm Welding fumes – 10 to 50 nm Diesel exhaust particles – (Small mode) 7 to 40 nm Carbon black for photocopier toner – 10 to 400 nm

Engineered nanoscale materials – “nanomaterials” Fullerenes – buckyballs – 1 nm: nanotubes – 1 to 5 nm x 10 µm Quantum dots for medical diagnosis– 5 to 20 nm Semiconductor wires for sensors – 10 to 100 nm diam. x 1 µm

NNI Clayton Teague presentation, 4/2/04

Some Initial Health Studies of Nanoparticles

• Lam et al. (2004) – washed 3 kinds of carbon nanotubes into lungs of mice; all caused lung granulomas

• Dupont injected nanotubes into rat lungs; 15% died (highest death rate seen in such studies)

• SMU – buckyballs cause extensive brain damage in fish

• Rice University – studies show nanoparticles bioaccumulate in living tissues

Specific Federal Projects on Implications

NIH/ NIEHS – support of the new National Toxicology Program, ~$3M multi-year project initiated in FY2004

Studies to evaluate the toxic and carcinogenic potential of test agents (quantum dots, nanotubes) in laboratory animals via inhalation exposure

EPA – Impacts of manufactured nanomaterials on human health and the environment, $4M in FY2004

Toxicology of manufactured nanomaterials Fate, transport, and tranformation of manuf. Nanomaterials Human exposure and bioavailability

NNI Clayton Teague presentation, 4/2/04

Nanotechnology and Society: Public Debate

Ubiquitous Nanosensors – Privacy of the individual

• What if the walls have eyes and ears?

• What if sensors can be attached to me without my knowledge?

• Is my health and genetic susceptibilities private information?

(continued)

Nanotechnology and Society: Public Debate

“Bots” – Self replicating nanomachines

• Is it feasible?

• What previous experience can we draw upon?

• Is responsible action needed?

(continued)

Nanotechnology and Society: Public Debate

“NanoAssistors” – Human-machine interfaces

• Are human assistive devices for the disabled appropriate nanotechnology to support?

• Should nanotechnology be used to enhance human performance?

− for warfighters?

− for athletes?

− for my children?

• Who decides?

(continued)