Revolutionary Color Filtering Using Fluorescent Polystyrene Beads

Brian Gallaspy Alan Pham

Huayu Zhou Sachin Mehta

Reno, Nevada

Introduction• Using solutions polystyrene beads of the following colors: red, blue, and

green we will print 5mm x 5mm squares on glass cover slips. We were previously printing on photo-paper, but Alan here will discuss more about that and why we made this change.

• Various combinations will be printed—layer on top of layer. For example, some of the combinations:

• Red Blue GreenRed Green Red

Green OR Red OR Blue

Green Blue

• These combinations, when analyzed using Photo-Luminescence Spectrometer from Ocean Optics, will result in different spectrums and wavelengths.

• The variable is the amount of layers of a certain color we put in a sample.

• These wavelengths will then be plotted on the C.I.E Chromaticity Diagram System.

• These molecules are capable of absorbing energy from photons (UV, vis.)

• Energy is absorbed by electron moving to unstable “excited state”

• When the electron relaxes to its ground state, energy is released as a photon corresponding to the difference in energy between the excited & ground state.

Photoluminescence• Molecules that fluoresce

contain conjugated π- bonds

• This means that the molecule has a structure that has alternating single and double bonds

• This structure allows electrons to be shared throughout the whole molecule, and energy states that are conducive to fluorescence.

Fluorescent Polystyrene Microspheres• Polystyrene is a

widely used polymer of the monomer styrene.• It can be made into

spheres ranging from 1μm – 1mm.• Upon these spheres,

fluorescent compounds are attached.

http://www.lifetechnologies.com/us/en/home/life-science/cell-analysis/qdots-microspheres-nanospheres/fluorescent-microspheres.html

C.I.E 1931 Color Space

Links physical pure colors (wavelengths) & perceived color of the human eye

Three ‘primary’ colors—red, blue, and green

Characterizes colors by a luminance parameter Y and a two-coordinate x,y system—which specifies any single point on the chromaticity diagram to the right

The various color combinations printed one on top of another will allow us to develop our own Chromaticity Color Triangle

http://www.color-theory-phenomena.nl/10.03.htm

Coordinates of Pure White

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/cie.html

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/photom.html#c2

Methodology The data points from the PLS

will then be inputted into a Matlab Program to yield a charted color map with the color’s specific coordinates.

After obtaining data coordinates from multiple samples we applied multivariate regression to obtain a ratio analysis.

With the newly obtained ratios, it was then possible to mix the respective amounts of polystyrene beads to try and achieve the desired coordinates for the color white x, y = (1/3, 1/3).

Using the Dimatix 2D inkjet printer, multiple layers of the fluorescent microspheres are printed onto a glass slide.

Varying layers of the three different fluoresced microspheres will yield a unique respective position on the C.I.E Color Space.

Each sample will then be analyzed with the assistance of Dr. Zhou, and a Photo-Luminescence Spectrometer by Ocean Optics.

Results – Pure Color Blue

Matlab Output of Chromaticity of Blue Polystyrene Microspheres

Results – Pure Color Green

Matlab Output of Chromaticity of Green Polystyrene Microspheres

Results – Pure Color Red

Matlab Output of Chromaticity of Red Polystyrene Microspheres

Results – Data Set I

Sample # 3 Analysis – 8 Green Layers and 1 Red Layer

Matlab Output of Chromaticity of Most Precise Sample from Data Set I

Results – Data Set II

Sample # 12 Analysis – 5 Red Layers, 10 Green Layers, & 5 Blue Layers

Matlab Output of Chromaticity of Most Precise Sample from Data Set II

Unforeseen Problems - For first attempts in data selection we implemented 1 in x 1 in cut cover class.

• These slides were un-treated and not cleansed—leaving us to question the validity of our samples.

• Thickness of these glass slides were 1.2 mm which brought extraneous light into our samples when analyzing using the Photo-Luminescence Spectrometer.

- Printer temperature settings had to be adjusted in order to obtain most reliable printing.

- Waveform manipulation was not constant for each time we printed. For example, after changing out the printer cartridge to another solution of polystyrene beads we would not obtain proper printing.

- Nozzle Clogging—sometimes leaving us with only one nozzle to work with. This added on extra, and wasted time, that could have been used to perform more valuable analyses.

Applications

The color white, as we know it, is not in the true sense white.

It lacks “purity”– in regards to being at the exact coordinates of (1/3, 1/3).

Major research is taking place as we speak to obtain this pure color and leading companies such as Samsung and Sony are at the forefront.

Determining the exact ratio of blue : red : green would make it possible to advance optics, engineering, and technology.

http://www.venturelighting.com/naturalwhite/naturalwhite_faqs.html

Thank you!

Now we will leave the

floor open to any

questions!