Nanotechnology

Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.

1 nanometer = 1 x 10-9 m

Some things we will discuss:

• How big are nanostructuresScaling down to the nanoscale

• How are nanostructures made?Fabrication, synthesis, manufacturing

• How do we see them?Imaging and property characterization

• Why do we care?Applications to science, technology and society

Introduction to Nanotechnology

Why do we want to make things small?

• To make products smaller, cheaper, faster and better by "scaling" them down. (Electronics, catalysts, water purification, solar cells, coatings, life-science, etc)

• To introduce new physical phenomena for science and technology. (Quantum behavior and other effects.)

How small are nanostructures?

Single Hair

Width = 0.1 mm

= 100 micrometers

= 100,000 nanometers !

1 nanometer = one billionth (10-9) meter

Smaller still

Hair

.

Red blood cell

6,000 nanometersDNA

3 nanometers

Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773)

...At length being at Clapham, where there is, on the Common, a large Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....

... the Oil tho' not more than a Tea Spoonful ...

... perhaps half an Acre

CHALLENGE: How thick was the film of oil?

Volume = (Area)(Thickness)

V = A t

It can be determined that the thickness is around 1 nanometer

A monolayer film (single layer of molecules)

Langmuir film

~1 nm thickAn Early Nanotechnologist!

Making Nanostructures: Nanofabrication

• Top down versus bottom up methods

• Lithography• Deposition• Etching• Machining

• Chemical• Self-Assembly

Lithography

MarkTuominen

MarkTuominen

MarkTuominen

(Using a stencil or mask)

Making a microscopic mask

Silicon crystal

Polymer film

Electron Beam

Nanoscopic Mask !

Example: Electron-Beam Lithography

Lithography

IBMCopperWiringOn aComputerChip

PatternedSeveral Times

NANOFABRICATION BY SELF ASSEMBLY

Block “A” Block “B”

10% A 30% A 50% A 70% A 90% A

~10 nm

Ordered Phases

PMMA PS

Scale set by molecular size

One Example: Diblock Copolymers

CORE CONCEPT FOR NANOFABRICATION Deposition

Template

EtchingMask

NanoporousMembrane

Remove polymerblock within cylinders(expose and develop)

Versatile, self-assembling, nanoscale lithographic system

(physical orelectrochemical)

DEVELOPMENT OF NANOFABRICATIONTECHNIQUES FOR PLASMONIC ARRAYS

template dots

rings holescylinders

How do we see nanostructures?

• A light microscope? Helpful, but cannot resolve below 1000 nm

• An electron microscope? Has a long history of usefulness at the nanoscale

• A scanning probe microscope? A newer tool that has advanced imaging

Television Set

eye

electron beam

TV screen

Light !electronsource

Scanning Electron Microscope

SAMPLE

ElectronBeam

DETECTOR

Scanning probe microscope

Surface

Vibrating Cantilever

PS/PEO

AFM image

µm(large )

Laser Beam

AFM, STM, MFM, others

Some Nanostructures

Image of Nickel Atoms Pushing Atoms Around

Nanotechnology R&D is interdisciplinary and impacts many industries

• Physics• Chemistry• Biology• Materials Science• Polymer Science• Electrical Engineering• Chemical Engineering• Mechanical Engineering• Medicine

• Electronics• Materials• Health/Biotech• Chemical• Environmental• Energy• Aerospace• Automotive• Security• Forest products

Making Small SmallerAn Example: Electronics-Microprocessors

Since the 1980's electronics has been a leading commercial driver for nanotechnology R&D, but other areas (materials, biotech, energy, etc) are of significant and growing importance.

Some have been around for a very long time:• Stained glass windows (Venice, Italy) - gold nanoparticles• Photographic film - silver nanoparticles• Tires - carbon black nanoparticles• Catalytic converters - nanoscale coatings of platinum and palladium

Applications to science, technology and society

Nanotechnology has enormous potential to change society. An estimated global research and development investment of nearly $9 billion per year is anticipated to lead to new medical treatments and tools; more efficient energy production, storage and transmission; better access to clean water; more effective pollution reduction and prevention; and stronger, lighter materials. And these are just a few of the more significant ways in which people are discussing using the technology.

Involved in making a manufacturing process environmentally benign.

An environmentally benign material or manufactured product that replaces toxic substances or minimizes raw materials.

Synthetic or manufacturing processes which can occur at ambient temperature and pressure.

Nanotechnology for pollution prevention

Use of non-toxic catalysts with minimal production of resultant pollutants.

Use of aqueous-based reactions.

Build molecules as needed --“just in time.”

Nanoscale information technologies for product identification and tracking to manage recycling, remanufacture, and end of life disposal of solvents.

End-of-pipe management and cleanup of pollution

Treatment & Remediation

Iron Treatment Walls…

Used in groundwater treatment for many years. Iron chemically reduces organic and inorganic environmental contaminants. Currently involves granular or “microscale” iron ( 50 mm or 50,000 nm).

and Nanotechnology

Nanosized iron enhances the reaction. Enhanced further by coupling with other metals (Fe/Pd)* on the nanoscale. Nano Fe0 is more reactive and effective than the microscale. Smaller size makes it more flexible -- penetrates difficult to access areas.

Welcome to NanoWorld!

Summary

Nanotechnology is ubiquitous and pervasive. It is an emerging field in all areas of science, engineering and technology.