1. 52300 Sensing and Actuation in Miniaturized Systems
Topics： Microlens array bio-sensing system
Professor：Cheng-Hsien  Liu
Students：Den-Hua Lee
Tsu-Wei Huang
Professor Liu, ladies and gentlemen.
My name is Tsu-wei Huang.
My partner is Den-hua Lee.
The topics of our presentation is “microlens array bio-sensing system.”
We select one paper from uTAS 2007 proceeding to present a method enhancing light efficiency of OLED with micro lens array.
And base on these reference we try to develop a novel micro optical bio-sensing array system.
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2. Introduction The Goal Discussion Conclusion
Contents
Introduction
The Goal
Discussion
Conclusion
The following will be our brief introduction, the goal we purpose. Discussion and conclusion.
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3. Introduction
Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays
A novel method to fabricate gapless hexagonal micro-lens array
Microlens array film with full fill factor for enhancing outcoupling efficiency from OLED lighting
The first reference show that we can enhancing the light out-coupling in OLED with ordered microlens arrays.
The second one present a method to fabricate hexagonal microlens array, There are no gap between each lens.
And this paper from uTAS 2007 try to combine both concept, and develop a new design with full fill factor.
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4. Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays
S. Möller and S. R. Forrest
The first reference was published on the Journal of applied physics.
J. of Applied Physics, 91 p (2002)
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5. Mold transfer process Si mold was etched in HNO3+CH3COOH+HF
A mold transfer process is used.
Left image show the structure of Silicon mold. Fabricating by wet etching.
Right image show the PDMS microlens array peeled off from the mold.
PDMS is a thermal curable elastomer.
Si mold was etched in HNO3+CH3COOH+HF
used Si3N4 layer as a mask
PDMS microlens array fabricated from the mold
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6. Image blurring due to the thickness Covered area is brighter
Attaching the MLA film on glass, and cover it on the paper print out.
Image result is slightly blurring due to the thickness.
But the font is still barely resolvable.
Attaching this microlens sheet on a 2.5cm X 2.5cm OLED panel.
Covered area is brighter.
Paper printout
Lens sheet covered
OLED with lens sheet covered
Image blurring due to the thickness
Covered area is brighter
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7. A novel method to fabricate gapless hexagonal micro-lens array
M.C. Chou, C.T. Pan, S.C. Shen, M.-F. Chen, K.L. Lin, and S.T. Wu
The second reference was published on the Sensors and acturators.
Sensors and Actuators A, 118, p (2005)
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8. fabricating half-spherical columnSi
Reflow process
of AZ4620 thick PR for
fabricating half-spherical column
Thick film photoresist is used to form the column structure array on si substrate.
The hemi-spherical shape was form by the reflow process.
Then fabricate the mold by electroplating.
PMMA is used for hot embossing process to be the microlens.
Ni as seed layer
Electroplate Ni-Co mold
CMP
Hot embossing PMMA
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9. Different shape with different fill factor
90%
45%
Different shape will result in different fill factor.
Distribution during reflowing will cause gapless hexagonal lens.
95%
100%
Different shape with different fill factor
Distribution reflowing to form gapless hexagonal lens
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10. Sequence of Ni-Co electroplating process
These image show the process during electroplating.
The gap is thinning as the time passing.
Sequence of Ni-Co electroplating process
Different gapless lens form by different distributions
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11. Laser spot form by microlens will be different due to the orientation of the microlens.
Laser passes through hot-embossed PMMA-based gapless hexagonal micro-lens.
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12. Microlens array film with full fill factor for enhancing outcoupling efficiency from OLED lighting
Hyouk Kwon, Youngjoo Yee, Chi-Hwan Jeong1, Hyo-Jin Nam, Ki-Won Park, Gun-Woo Lee, and Jong-Uk Bu
Now the paper we select from uTAS 2007 proceeding.
uTAS proceeding, 2EK5P, p (2007)
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13. Micro Lens Array provide brightness increasing
From the former lecture.
We know that
Micro Lens Array provide brightness increasing
Higher fill factor, higher efficiency
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14. Trench structure keep lens’ shape closing to half-spherical
Conformal coating process decrease the height of lens
In this paper, a trench structure is purpose.
The sag height will be loss due to the conformal coating. It doesn’t look like hemi-spherical.
But, the trench structure could keep microles close to hemi-spherical. The efficiency could be enhanced.
Outcoupling efficiency according to the sag ratio
Applying trench to keep higher sag height
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15. MLA is made by UV stamping on transparent PET film
Very similar mold transfer process. Just add the trench structure on the glass substrate.
Microlens were made by the PET film.
MLA is made by UV stamping on transparent PET film
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16. Cover this MLA film on OLED, the luminous flux is increased.
And the chromaticity doesn’t change too much.
Luminous Flux means the total amount of radiation energy comes from the light source.
Chromaticity means what color this panel looks like from the human eyes.
Microlens array enhance the light efficiency 30% without changing too mush chromaticity.
31.3% improvement
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17. OLED with MLA looked brighter
You can see the area covered with MLA will be more brighter, either orange or blue panel.
OLED with MLA looked brighter
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