New Materials and Applications of Nanotechnology

Universeum4th April 2006

New Materials:

Nanomaterials (TiO2, Ag/Au, Carbon)

Nanocomposites (Carbon)

Surface-modified materials (biomimetics)

Visions of the future

Stronger, lighter, more environmentally friendly, less wastage, smaller, faster, new functionality

Titanium Dioxide Nanoparticles

Ca. 20 nm diameter

Photocatalysts:UV-vis light

oxidation of hazardous compounds in air and water

Sun-screens and cosmeticsSelf-cleaning surfaces (windows and walls): photocatalytic reaction breaks down organic material (acts like bleach). Hydrophilic surface allows rain water to wash off directly –self-cleaning. Also fog-free mirrors.

Self-cleaning windows and other surfaces

Uses nanometre thick layers of titanium dioxide particles

Solar Cells(Grätzel)

Dye molecules absorb sunlight. Excited electrons are transferred to TiO2nanoparticles. They rapidly pass through the particle network to the electrode.

The ”holes” in the dye molecules are filled by low energy electrons from the iodine.

Cheap and easy to produce

(see ”Teaching Nanotechnology in the HIgh School Curricuum”)

Silver NanoparticlesSilver’s antimicrobial properties have been known for centuries.

In ancient Greece and Rome, silver containers were used for perishable liquids because they retarded the growth of food-spoiling organisms.

Western medicine has been using eye-drops containing silver to prevent infections in newborn babies’ eyes for more than a century.

With nanoparticles less material is needed for the same performance. Particles can be functionalised and incorporated inpolyemers and textiles

Nanohorizons

Ag nanoparticle containing textiles for socks

Nanoparticles for Cancer Therapy

Particles functionalised to target tumour cells.

Gold sphere resonantly excited with laser light that is not absorbed by other material in the body (resonant plasmon excitation). Heat is transferred to tumour cell and kills it.

Zigzag-tube Armchair-tubeChiral-tube

Computing power doubles every 18 months

2nd Law: The cost of a manufacturing plant doubles with every new generation

Electronics

Problems: fundamental physics, heat generation, cost

ITRSITRS roadmaproadmap

C

Why Carbon for Nanoelectronics?

Kevin Teixeira, Intel:

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

But the more interesting question is,´What do you add tosilicon 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

Human hair

IBM has built the first electronic integrated circuit built around a single nanotube

Science, March 24th 2006

Carbon Nanotube Nanorelay

high Q oscillator, logical switch, bistable memory element, Mechanical resonance frequency in GHz range, switching speed could be faster.

J. Kinaret et al. (S. Viefers) , Appl. Phys. Lett. 82, 1287 (2003)

L.M. Jonsson et al., J. Appl. Phys. 96, 629 (2004)

Carbon nanotube Source electrode

Drain electrodeGate electrode

Contact Mode Nanorelay J. Kinaret

Kinaret et al, Appl. Phys. Lett. 82 (2003) 1287; Jonsson et al., J. Appl. Phys. (2004)

PMMA

SiO2

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(b)

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Acid free method to make suspended structure: S. W. Lee et. al Appl. Phys. A 78, 283 (2004)

Nanorelay Fabrication

68 were made

38 remained suspended after processing

Alignment condition : 13MHz, 16V(peak to peak) for 10 s

S.W: Lee et al., Nano Lett. 4 (2004) 2027

0 5 10 15 20 25

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The resonance frequency can be tuned by several GHz by tuning the gate voltage.

”Nanotubes are stronger than steel”

What does this mean?

Elasticity (how hard is it to stretch) and toughness (tensile strength) are important mechanical properties of materials.

The Young’s modulus is a measure of the intrinsic elasticity of a material (i.e. How hard it is to stretch).

For good nanotubes the Young’s modulus is ca. 1 TPa

This is as stiff as diamond and about 100 times stiffer than steel.

Many materials are stiff but brittle (low tensile strength). Most materials that are not brittle are not particularly strong.

Spider’s silk is an interesting material: it is not brittle (it can stretch beyond 30% of its rest length) and is relatively strong with a tensile strength of 1 GPa. The Young’s modulus is ca. 100 MPa

Nanotubes can stretch beyond 20% (elastic limit 5%, cf 0.2% for steel) of their rest length, can be bent double and tied in knots without resulting defects.

EndoNanotubes have an unprecedented combination of stiffness and toughness.

They are the strongest known fibres under tension

465 MPa/(g/cm3)Steel 125 MPa/(g/cm3)Al alloy 250 MPa/(G/cm3)

Nanotube Sheet/Yarn

200 GPa1 TPaSWNT3 GPa200 GPaCarbon Fibre1 GPa100 MPaSpider Silk400 MPa200 GPaSteelTensile StrengthYoung’s modulusMaterial

SWNT: ca. 100 x stronger than steel with 1/6 of the weight

Zhang et al., Science 309 (2005) 1215

Use as incandescent light source:

Blackbody radiation at 1410 K

Welding of 2 5mm plexiglass plates

Top cover Safety vent

Gasket

PTC

Insulator

Anode can

Insulator

Cathode Anode

SeparatorAnode lead (Cu)

Cathode lead (Al)

Structure of LIB practical cellStructure of LIB practical cell

Ref :Ref : Sony’s catalog, Lithium ion rechargeable battery, ACG-4012-N-9707-P3-002, 1977. Sony’s catalog, Lithium ion rechargeable battery, ACG-4012-N-9707-P3-002, 1977.

M. Endo, T. Karaki, T. Fujino New ceramics 1988; 4: 46-52, (In Japanese)M. Endo, T. Karaki, T. Fujino New ceramics 1988; 4: 46-52, (In Japanese)

19861986 20002000

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M. Endo

Principle of operation of Li-ion-BatteryPrinciple of operation of Li-ion-Battery

LiCoO2 Graphite

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LiCoO2 Graphite

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Principle of operation of Li-ion-BatteryPrinciple of operation of Li-ion-Battery

LiCoO2 Graphite

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Principle of operation of Li-ion-BatteryPrinciple of operation of Li-ion-Battery

5μm

Cu foilCu foil

MWNTMWNT

M. Endo, Y. A. Kim, T. Hayashi, K. Nishimura, T. Matsushita, K. Miyashita and M. S. Dresselhaus, Carbon 39, 1287-1297 (2001).

7070

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Artificial graphite (HTT2500℃) with CNT

Cyclic characteristics of synthetic graphite as a function of weight percent of CNT (MWNT)

Cyclic characteristics of synthetic graphite as a function of weight percent of CNT (MWNT)

M. Endo, Y. A. Kim, T. Hayashi, K. Nishimura, T. Matsushita, K. Miyashita and M. S. Dresselhaus, Carbon, Vol.39, pp1287-1297, (2001).

M. Endo, Y. A. Kim, T. Hayashi, K. Nishimura, T. Matsushita, K. Miyashita and M. S. Dresselhaus, Carbon, Vol.39, pp1287-1297, (2001).

Li-Polymer Battery (LIB)

• Safety ;solid electrolyte• No liquid leakage• Light weight and thin

thikness(1mm)• Shape-design freedom

(back side of LC display)

http://ascii24.com/news/i/topi/article/1999/10/12/604874-000.html

MWCT is an essential component for “LIPB”

Prof. Endo with his CNT applications

Sports Equipment

Babolat VS CNTControl

Racquets

Flat panel displays based on CNT electron field emission

A Space Elevator?A space elevator would provide cheap access to space.

1960: Y. Artsutanov

1979 Arthur C. Clarke ”The Fountains of Paradise”

BUT: Cable needs to be extraordinarily strong to support its own weight over distances of thousands of km. A steel cable that was 1 mm wide at the surface would need to be 40 billion km in diameter at the satellite to avoid breaking!

1. Base tower on Earth

2. A heavy weight orbiting the Earth as counter weight

3. A cable connecting the tower to the weight

4. A spacecraft to ride the cable into orbit

Animation from http://www.isr.us/SEanimation.asp

Surface Modified Materials

Control of Bio-fouling

Biofouling is the accumulation of unwanted microorganisms, plants and animals on man-made surfaces- such as those exposed to the marine environment.

Fouling has been controlled traditionally by antifouling paints that contain biocides

Modify surfaces at the nanometer level to avoid the microorganisms attaching themselves

Another Vision of the Future

Institute for Soldier Nanotechnologies

http://web.mit.edu/isn/aboutisn/isnvideo.html

Some interesting links

Teaching Nanotechnology in the High School Curriculum (http://www.thenanotechnologygroup.org/docs/Teaching%20Nanotechnology%20in%20the%20High%20School%20Curriculum.pdf)

Nanotechnology helps solve the world's energy problems (Nanoforum Report) (pdf on web page)

The Space Elevator: Institute for Scientific Research Inc.(http://www.isr.us/research_es_se.asp)