Biology of Eye
Prepare a 200- to 300-word history about the National Critical
Technology (NCT) technical application your team has selected to solve a local or
Cite three detailed examples of research done
in the past 3 to 5 years which focused on the NCT technical application your team
Nanotechnology is defined by the
National Science Foundation as
the research and technological development at the atomic, molecular or macromolecular
levels, in the length scale of approximately 1-100 nanometer range, to provide a
fundamental understanding of phenomena and materials at the nanoscale and to create
and use structures, devices and systems that have novel properties and functions
because of their small and/or intermediate size.
Richard Feynman, in a 1959 speech, "Thereís
Plenty of Room at the Bottom", suggested that it's possible to build
machines small to enough to manufacture with atomic precision. His work was continued
by Eric Drexler, who introduced the word "nanotechnology" in his 1986
of Creation". His book accrued so much celebrity that nanotechnology
research funding in the National Nanotechnology Initiative.
Since our national critical technical application is nano-optics we began by investigating
the developing technologies of photonic crystals, liquid crystals, and moth-eye
diffraction gratings to diminish or eliminate unwanted glare on the windshield.
- Lord Rayleigh studied electromagnetic wave propagation in simple,
one dimensional photonic crystals in 1887; yet it was not until
1987 that Eli Yablonovitch and Sajeev John suggested that three dimensional
crystals could be used to reflect specific wavelengths.
1888 Friedrich Reinitzer discovered the concept of liquid
crystals. He found that cholesteryl benzoate has two melting points- the first is
a cloudy liquid and the second is a clear liquid. The cloudy liquid has the optical
properties of a crystal and is the precursor to modern liquid crystals.
- In 1967, C.G. Bernhard
and D. Ottosan, of the Karolinska Institute in Sweden, discovered the diffraction
properties of the nanostructure of a moth's eye. MacDermid Autotype, an affiliate
of the Fraunhofer-Gesellschaft, developed and patented the first artificial "moth-eye
diffraction grating" in
1999 and calling it
MARAG (Moth-eye Anti-Reflective, Anti-Glare).
Despite the promising nature of the first two technologies our team chose moth-eye
gratings due to inherent limitations. The behavior of light becomes too difficult
to predict when many photonic crystals are applied to a large surface and liquid
crystals are temperature dependent making it difficult for them to withstand outdoor
principal investigator's name, and
institution where the research is or was being conducted.
Prior to citing our related grants, we would like to present three patents granted
by the US Patent Office that directly support our project's goal.
Based on the research your team has done,
explain how the NCT application chosen has advanced scientific knowledge.
Now we would like to present three grants that support our product and its development:
- #6647166 Transition
Metal Switchable Mirrors by Pam Siedenman. This technology employs a thin film
coating on glass that, when exposed to a small electric current, will change from
transparent to reflective and all levels in between. The coating is a metal alloy
containing magnesium and a transition metal instead of rare earth metals, as other
companies have. The use of the alloy reduces cost and increases effectiveness. Transition
Metal Switchable Mirrors (TMSM) allow for better transmission of light and 75 to
10 percent better reflectiveness than current films. Current windows only have the
ability to darken but not become opaque, the current windows also "have little effect
on infrared radiation". The technology if used in cars could help cut up to 80%
of the heating and cooling equipment.
- #4965121 Solar
control layered coating for glass windows by Young, Paul I. and Wolfe, Jesse
D. This "stack" of glass which has five layers minimizes the amount of radiation
to come through the vehicle so that it barely reached the legal level of glass.
This glass allows a proportion of the sun rays while the remainder is reflected
by a coating. Typically, the coating that is used would be a neutral color which
is desirable for trucks and automobiles.
- Patent # 6958207 Method
for producing large area antireflective microtextured surfaces by Niyaz Khusnatdinov
and Tanwin Chang. This patent involves producing a "mask" to create a microstructure
surface with antireflective properties. The process involves using photolithography
to create a pattern in a light sensitive material. The material is then processed
to obtain the micro-textured surface. The surface is made up of many peaks and valleys.
The peaks can be arranged in any design desired. The antireflective properties are
designed for visible light. The process is readily scaled up to large areas in inexpensive
Two grants were presented by the Engineering and Physics Science Research council
- A two-year grant was awarded in 2006 by the National Highway Transportation Safety
Mark S. Rea, Ph.D, the director of the Lighting Research Center at Rensselaer
Polytechnic Institute, in the amount of $890,012.00. This grant was awarded for
researching the causes and effects of headlight glare and developing technological
solutions. LRC has already conducted extensive research on the causes of headlight
glare. They have found that the high wavelength (blue light) of the light from HID
bulbs helps to increase visibility for the driver using them, but also increases
the amount of discomfort glare experienced by other drivers. They have also found
that glare negatively affects both sides of the peripheral vision of drivers. This
current research project will further their concepts of glare, and the end result
will be a form of headlamp designed to maximize luminous intensity of the road while
meeting standard requirements and minimizing glare.
- In April of 2004, two researchers were awarded $250,000 for their investigations
into moth-eye diffraction as a glare reducer.
Byung H. Kim and Justin Piccirillo won the
Carrot Capital Business Plan Challenge, a competition between 20 teams
from business schools all across the country. The University of Massachusetts at
Amherst gave these two men the ability to produce and develop their ideas. Their
idea will drastically reduce the cost of anti-reflective coatings for LCD monitors
and LCD TVís - from thirty dollars per square foot to fifty cents per square foot.
- A two-year, 155,646 British Pounds ($304,116.71 US Dollars) grant was awarded to
Professor C Wilkinson of the University of Glasgow to investigate mechanical
methods of imprinting nanostructures over large areas. One of the technologies investigated
was the anti-reflective properties of the moth-eye coatings. Although the grant
began in 1997 and ended in late 1999, putting it outside the designated timeline, it is relevant to this project because of the
large scale of imprinting.
- A three-year grant starting on November 8, 2004 worth 430,639 pounds (846,377.891
US Dollars) was awarded to
Professor AJ Turberfield of Oxford University for his investigation into
creating photonic crystals with a predetermined interference pattern. In this grant
they will be investigating the doping of photonic crystals to create a band gap
for a given frequency. Through the use of a 3D-holographic laser an interference
pattern is formed on a light sensitive material. The researchers also are investigating
the effect of structural defects on the optical properties of the crystals. The
results of this research will be useful for optical semiconductors.
Nanotechnology has greatly affected the world of optics. Applications of nanotechnology
that we investigated were in the form of moth-eye diffraction gratings, photonic
crystals, and liquid crystals.
- Moth-eye diffraction grating applications by
MacDermid AutoType Optical Films
- Photonic crystal applications
Photonic crystals have potential application in optical fiber, optical sensors,
atomic optics, and fiber lasers. However, the most widespread application is digital
optical communications, due to massive information traffic
of today's world. Their ability to reflect, trap, and guide light of certain wavelengths
allows the photonic crystals to be integrated in electric circuits of communication
devices. Currently, when data is sent over an optical wire it is converted from
an electrical signal to an optical signal, and back to an electrical signal. As
data traffic increases, either the more optical fibers are installed or data is
sent over existing fibers, and more robust electronic devices are installed to process
larger amounts of optical signals to electrical signals. Photonic integrated circuits
could solve this problem by routing incoming optical signals without converting
them to electrical signals. This device would put many components on the receiving
end of the wire into one circuit, thus cutting costs of optical technology.
Photonic crystals can also be used in the laser industry. For example, in ultra
high power fiber systems, light from a powerful laser could be directed by photonic
crystals to a cutting head used in surgery. Another example would be when
a photonic crystal fiber is used to guide atoms or particles over long distances,
forming the basis of fiber devices that carry matter. Photonic crystals have also
improved the light extraction efficiency in
light emitting diodes (LEDs), making them brighter and more energy efficient.
Another potential application of photonic crystals is capturing fingerprints.
Using the crystal's elastic property, the new technology would capture a fingerprint
in multiple colors. This will be done by elastically deforming crystals to block
out partial light, certain wavelengths, and thus certain colors. The new application
would capture the print in still images and video, recording pressure patterns and
surface ridges not visible to the naked eye. Even if a plastic replica was made
of a person's finger, the pressure image would look different on the model because
plastic material is less soft than a normal finger. From a biometric perspective,
the technology is a major improvement in security. The sensor technology can also
be applied to airbag mechanisms in cars, or even strain and torque sensors on support
beams of high rise buildings.
- Liquid crystal applications
The most common use of liquid crystals is
liquid crystal displays (LCD). Liquid crystal displays are used for things
as complicated as computer monitors and television screens, but also for things
as simple as pocket watches and cell phones. LCDs are made up of two plates
of glass or plastic with a thin film of liquid crystals between the two. The plates
of glass are normally created with transparent electrodes made out of indium tin
oxide. These electrodes make it possible to establish an electric field across the
crystals. The final step is to place crossed polarized filters on either side of
the glass plates which will allow only the polarized light modified by the liquid
crystals to be transmitted.
Reflective twisted nematic liquid crystal display.
- Vertical filter film to polarize the light as it enters.
- Glass substrate with ITO electrodes. The shapes of these electrodes will determine
the dark shapes that will appear when the LCD is turned on. Vertical ridges are
etched on the surface so the liquid crystals are in line with the polarized light.
- Twisted nematic liquid crystals.
- Glass substrate with common electrode film (ITO) with horizontal ridges to line
up with the horizontal filter.
- Horizontal filter film to block/allow light passage.
- Reflective surface to send light back to viewer.
Image and caption courtesy of The Best Links
Liquid crystal thermometers make use of
cholesteric liquid crystals whose alignment axes (or directors) form a helical
pattern which is reliant on temperature. Consequently by looking at what shade of
color is being emitted from a crystal thermometer, you can tell the temperature
of whatever you are trying to calculate. This temperature dependence is also the
basis of "mood rings."
A use of liquid crystals that is currently being researched is optical imaging.
In optical imaging liquid crystal cells are placed between two layers of photoconductors.
Impinging light heightens the photoconductor's conductivity, creating an electric
field across the liquid crystals that is dependent on the intensity of light. The
pattern coming from the liquid crystals is then transmitted by an electrode and
recorded as an image.
"Liquid crystals are already used commercially for making windows which turn
from opaque to transparent with the application of an electric field..."1
There doesn't appear to be any way liquid crystals could be used to make an antireflective