building green in the 21 st century engineering with nanotechnology

Building Green in the 21st Century

Engineering with Nanotechnology

Why Green? Why Now?

• What are some challenges?– Global Warming?– Air and Water

Pollution– Landfills– Nonrenewable

Resources

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Global Warming

• Greenhouse gases (especially CO2)

• Natural cycle or human caused?– Can we wait?

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Pollution Challenges!

• Ozone

• Acid rain

• Drinking water

• Chesapeake BayImage from stock.xchng (http://www.sxc.hu/)

Landfills!

• Take space

• Produce methane gas (global warming)

• Add to water pollution

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Nonrenewable Resources

• Oil and Natural Gas Imports

• Mining for coal and mineral deposits

• Making electricityImage from stock.xchng (http://www.sxc.hu/)

Buildings Waste and Pollute!

• 43% of CO2

• 40% of Landfills

• 40% of Electricity

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What Can We Do?

• Live in caves or tents?

• Ignore the challenges?

• Practice the three “R’s”?

• Innovate and Invent new solutions? Image from www.stockxpert.com

Can Nanotechnology Help?

• Different Approach to Science and Engineering– Building blocks invisible to human eye

• Not new to Nature

ORbright idea

potential disaster

What is Nanotechnology?1. 1 item (usually 2 to 3) is 1 – 100 nm in

size.

2. Substances behave differently at the nanoscale!

3. Control or manipulate at the nano scale.

How Small is Small!?

Comparing one hundred nanometers to the size of a soccerball is like comparing a soccerball to the size of the earth!

100 nm

http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

Let’s Compare!

• How small is a human hair (diameter)

• Compare this to a nanotube (4nm diameter)

Surface Area/Volume Surface Area/Volume

Ratio increases as Ratio increases as size decreases size decreases

Solubility and Solubility and Reactivity Reactivity IncreaseIncrease

Video ClipVideo Clip

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Everything is Sticky

Internal Forces Dominate Over Gravity

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Appearances May Deceive

• Optical properties vary at the nanoscale.Image source: http://mrsec.wisc.edu/Edetc/SlideShow/slides/nanoparticles/Au_nanoshells.html

Mother Nature

Mother Nature has used nanotechnology for millions of year.

Living LED’s

http://news.bbc.co.uk/2/hi/science/nature/4443854.stm

Butterflies figured out how to emit light 30 million years ago.

Fluorescent patches on the wings of some butterflies work much like light emitting diodes (LEDs).

Fluorescent patches on the wings of some butterflies work much like light emitting diodes (LEDs).

Wings are Colorful and Hydrophobic!

The butterfly’s wing in the picture isn’t getting wet.

The butterfly can thank its nanoscales.

Water droplet

Look, Mom, I’m dry!

http://nanotechweb.org/articles/news/1/11/5/1/0611102

“Like Water Off of a Duck’s Back…

As the Saying Goes…

This picture shows water droplets on a wood surface treated with "Lotus Spray“, a nanotechnology product modeled after the butterfly wing and lotus leaf, which has made the surface extremely water-repellant (superhydrophobic).

The white bar on this nanoscopic view of a butterfly wing is 1 µm.

The white bar on this picture of a butterfly wing is 1mm long.

Or a Butterfly’s Wing!

Building Green with Nanotechnology

• How?

• When?

• Where?

Heating and Cooling

• Use HUGE amount of energy

• Insulators trap air

Nanotech Insulators

• Trap air better• High Surface Area

to Volume Ratio• Examples:

– Spray or paint on– Aerogel– Window Film

Printed with permission http://www.nansulate.com/

Lighting

• Uses almost one-third of energy

• 95% wasted as heat

• Fluorescent bulbs contain mercury

• Light-emitting Diodes (LEDs) safer and more efficient

LED FUNDAMENTALS

• Semiconductor material

• Electrons flow one direction (diode)

• Photons released • Color depends on

material/band gap

Atomic Level

LED’s Today

ACTIVITY

VS

Safety

• Avoid placing incandescent bulbs against flammable surfaces.

Procedures

• Turn off room lights.

• Measure temperature (oC) and illuminations (lumens). Lights off.

• Measure temperature (oC) and illuminations (lumens). Lights on.

• Record “raw data” (first part of data sheet)

INCANDESCENT VS LED ILLUMINATION

RED WHITE BLUE

INCANDESCENT

AVERAGE #DIV/0! #DIV/0! #DIV/0!

LED

AVERAGE #DIV/0! #DIV/0! #DIV/0!

INCANDESCENT VS LED TEMPERATURE RANGE

RED WHITE BLUE

INCANDESCENT

AVERAGE #DIV/0! #DIV/0! #DIV/0!

LED

AVERAGE #DIV/0! #DIV/0! #DIV/0!

RELATIVE EFFICIENCY (lumens/temp range)

RED WHITE BLUE

INCANDESCENT

AVERAGE #DIV/0! #DIV/0! #DIV/0!

LED

AVERAGE #DIV/0! #DIV/0! #DIV/0!

LED Efficiency (lumens/watt)

LEDs are highly efficient compared to other light sources.

Organic LEDs

• Small applications today

• Potential to mimic natural light

• Flat or curved• Potential to be more

efficient and less expensivePhotos from stock.xchng (http://www.sxc.hu/)

Steel and Concrete(and Wood?)

http://www.indigo.com/models/gphmodel/minit-carbon-nanotubes.html"> zig zag, chiral and

armchair carbon nanotubes</a> courtesy of Indigo®; Instruments.

Other Applications

• Glass

• Plastics

• Drywall

• Wiring

• Roofing Tiles

• Sensors

Review

• Why Green? Why Now?

• What is nanotechnology and how can it help?

• How do LEDs work?

• Environmental and human health concerns

Thank You