Nanotechnology

Eleanor CampbellDept. of Physics, Göteborg University

What is Nanotechnology ?Nano: 10-9; ”Dwarf”

• 0,000 000 000 000 000 000 000 000 000 000 000 01 meter Plancklängden, strängteori

• 0,000 000 000 000 000 001 meterElementarpartikelfysik; elektroner, protoner, ...

• 0,000 000 000 000 01 meterKärnfysik

• 0,000 000 000 1 meterAtomfysik

•1 meterKondenserad materias fysik, biofysik, geofysik...

•100 000 000 000 000 000 000 000 000 meterAstrofysik, kosmologi

Length Scales in Physics

Nanofysik, kemisk fysik..0,000 000 001 meter

Size Comparison

Earth 10 m7

Football 0.1 mFullerene

10 m-9

10

10

-8

-8

1 nm

100 000 nm

Nanotechnology:

Nanostructures are at the confluence of the smallest human-made devices and the largest molecules of living things. Nanoscale science and engineering refer to the fundamental understanding and resulting technological advances arising from the exploitation of new physical, chemical and biological properties of systems that are intermediate in size between isolated atoms and molecules and bulk materials, where the transitional properties between the two limits can be controlled

M. Roco, NSF (2001)

+Ze

-e -

e

-eAtom

Bulk

Multidisciplinary Research & EngineeringPhysics - Chemistry - Biology – Medicine –

Computer Science - Materials Science - Engineering

Material on the nanoscale is not just smaller it is also fundamentally different (”a special kind of small”):

Properties can be very dependent on the number of atoms

Quantum effects can become important

Richard FeynmanTheoretical Physicist

NP 1965 for QED

”What would the properties of materials be if we could really arrange the atomsthe way we want them? They would bevery interesting to investigate theoretically. I can't see exactly what would happen, but I can hardly doubt that when we have some control of the arrangement of things on a small scale we will get an enormously greater range of possible properties that substances can have, and of different things that we can do. ”

1959 ”There is Plenty of Room at the Bottom”

The Beginnings of Modern Nanotechnology

Modern Nanotechnology Laboratory

Early Nanotechnologists

Egyptian Gold Workers

Egyptian Pottery Makers

Medieval Stained Glass Windows also make use of Metallic Nanoparticles to Produce the Strong Colours

The properties of metallic nanoparticles are very dependent on size.

The difference today is that we understand the physics behind the phenomenon and can control the size, shape and behaviour of the particles to a much greater extent

Gold and Silver nanoparticles have plasmon resonances in the visible range. The resonant frequency depends on the size of the particles (also on shape and surrounding material)

Surface Plasmon in a Metallic Nanoparticle

Dark Field Image of Ag Nanoparticles in Optical Tweezer Setup

Particle A is trapped and moved by a laser beamThe colour changes when the 2 particles come close

M. KällD. Hanstorp

Chalmers/GU

Qdot: using functionalised CdSe clusters for labelling biological

materials.

The colours of the particles depend on their size -used instead of dye molecules

Double-labeling of mitochondria andmicrotubules in NIH 3T3 cells

Two Approaches: Top Down and Bottom Up

The meeting of these 2 approaches is opening up many exciting opportunities

Two Approaches to NanotechnologyTop Down

Bottom Up

lithography

Self-assembly

If we have been making use of ”nanotechnology” for thousands of years why is it such a hot topic now???

It is only very recently that we have been able to see and manipulate individual atoms

This is extremely important to understand how the manipulation of material on the atomic/nanometer level can lead to new properties

To manipulate material on the atomic level it helps to ”see” the atoms

High resolution electron microscopy has made great advances and it is now possible to see individual atoms, even as smal as Li (1Å resolution).

Scanning Tunnel Microscope

Binnig and Röhrer, NP 1986

Possible to ”see” and MANIPULATE individual

atoms

Iron atoms on Copper

Don Eigler (IBM)

”atom”

Catalytic behaviour of Palladium Clusters

C2H2 -> C4H6, C4H8 or C6H6

U. Heiz, Ulm

Catalytic Converters:Clusters of platinum, rhodium and palladium atoms break down unwanted exhaust products, CO, hydrocarbons and NOx

Other Catalytic Applications:

”Open Sesame: The Neorest's lidautomatically rises when one approachesit. Ladies need not worry, as theautomated seat then waits to see if one needs to sit or stand.”

Gold clusters have been used in Japanese hi-tech

toilets since 1992 as ”odour neutralisers”

graphitesp2 hybridised

diamondsp3 hybridised

Carbon Clusters: Fullerenes

”Buckminsterfullerene”

discovered in 1985

Nobel Prize in Chemistry, 1996

Produced as purified material in 1990

The extreme flexibility of the carbon atom lies behind all of organic and bio-chemistry. It is also responsible for the wide range of nano-carbon materials that are studied today.

Where it started. Astrophysics/chemistryGas Clouds in Space:

What molecules are present?

Kroto: µ-wave spectroscopy of cyanopolyynes.

These long chain molecules (consisting of C, H and N) are found in interstellar gas clouds. Kroto saw signatures in µwave spectra from carbon-rich stars that indicated they could also be present there, and were probably formed, in these environments.

He wanted a way to test the formation of these molecules under conditions that would be close to the interior of red giant stars.

Smalley: well-known chemical physicist who had made pioneering studies in molecular laser spectroscopy. He was an excellent ”machine builder”

Smalley had developed a method for making clusters of atoms frommaterials that were difficult to vaporise: Smalley source

Could this apparatus mimic the conditions in carbon-rich stars?

Curl, Kroto and Smalleys discovery, 1985

Suggestion that hollow, cage-like structures could explain the ”magic numbers” in the mas spectrum

Isaac Asimov: ”The most exciting phrase to hear in science, the onethat heralds the most discoveries, is not 'Eureka!' but 'That's funny...' ”

A new form of pure carbon

Kroto named the new molecule”Buckminsterfullerene”

Geodesic Dome designed by R. Buckminster Fuller

Krätschmer and Huffmans breakthrough

Macroscopic production of fullerene-containing soot using electric arc discharge

C60 and C70 are soluble in benzene

1990

Fullerene crystals

NMR (13C) C60 C70

Medical Applications of Fullerenes(C-sixty)

Water soluble contrast agent for magnetic resonance imagingFullerene-based protease

inhibitor (HIV)

Nanospeed Badminton Rackets: Nano-Powered by Fullerene for more repulsion and speed from a compact swing. The Yonex nano – structure uses nano – sized particles of fullerene and carbon. The result is a very fast head speed creating maximum power.

Yonex Badminton Rackets

Actually, the fullerenes don’t survive – they are simply being used as a convenient form of pure carbon!

"Helical microtubules of graphitic carbon", S. Iijima, Nature 354, 56 (1991)

MWNT discovered in 1991 by Sumio Iijima– Diameter of ~5-10 nm– Concentric cylinders of

carbon with a length of several mm

SWNT in 1993

• light weight and record-high elastic modulus

•strongest fibres that can be made

•high thermal conductivity (as good as diamond)

•metallic or semi-conducting (depending on geometry)

Why nanotubes?

New ”nanomaterial” with a wide range of interesting properties

Bulk material is interesting for composite materials e.g. smart clothing, conducting paper, modifying polymer properties......

Quasi-one dimensional structures - Theoreticians love them!

Västra Götaland

Nanotube Dimensions

Scaled to 10 cm diameter a typical nanotube would reach from Göteborg to Uddevalla

(0,0)

Ch = (10,10)

Wrapping (10,10) SWNT (armchair)

a1a2 x

y

Animation: Shigeo Maruyama, Tokyo University

(0,0)

Ch = (10,5)

Wrapping (10,5) SWNT (chiral)

a1a2 x

y

(0,0)

Ch = (10,5)

Wrapping (10,5) SWNT (chiral)

a1a2 x

y

Animation: Shigeo Maruyama, Tokyo University

Zigzag-tube Armchair-tubeChiral-tube

All Armchair (n,n) tubes are metallic

Zigzag tubes (n,0) are metallic if n is a multiple of 3

Chiral tubes are semiconducting, bandgap scales with 1/d

or metallic if n-m = 3q

2/3 semiconducting1/3 metallic

C. Dekker

metal-semiconductor junction

Possibility for carbon-based nanoelectronics

Computing power doubles every 18 months2nd Law: The cost of a manufacturing plant doubles with every new generation

Future Electronic Applications

Kevin Teixeira, Intel:

”We often get asked,´What comes after silicon?´

But the more interesting question is,´What do you addto silicon to do something new?´

Carbon nanostructures are one of the most promising future possibilities to combine with and expand CMOS capabilities

•dimensions (nm)

•electronic properties

•mechanical properties

•thermal conductivity

•ease of production

Field Effect TransistorerAvouris, IBM

One major aim is to find ways to make new nanomaterials ”self-assemble” to produce materials with novel properties

Semiconductor nanowires, LundCarbon nanotubes

e.g. Learn how to grow nanodevices on Si chips

Butyl nanoparticles are inserted into clay to keep the layers apart

Babolat VS NCTControl

Racquets

Another aim is to incorporate nanostructures into or onto normal ”bulk” material to change the properties

Nano-tex

Billions of tiny whiskers create a thin cushion of air above the cotton fabric,smoothing out wrinkles andallowing liquids to bead upand roll off without a trace.

Self-cleaning lotus leaf

Nanostructures surface reduces contact area and makes super hydrophobic material

Nanotechnology

Understanding, control and exploitation of the chemical, physical and biological properties of matter in the transition region between atom/molecules and bulk

Is not just about making small things

The tools of Nanotechnology

New Materials and New Applications

Nanotechnology and the environment (including health issues) followed by lab visit (Chalmers/GU)