Core-Shell Nanoparticle Generation Using Laser Ablation Vanessa Coronado, Westside High School, Houston ISD Dr. Sy-Bor Wen/ Assistant Professor and YoungKyong Jo/ Ph.D. student Dept. of Mechanical Engineering

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Core-Shell Nanoparticle Generation Using Laser
AblationVanessa Coronado, Westside High School,
Houston ISDDr. Sy-Bor Wen/ Assistant Professor
and YoungKyong Jo/ Ph.D. student Dept. of
Mechanical Engineering
http//www.istm.cnr.it/ponti/NJC06.html
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• Dr. Sy-Bor Wen, Department of Mechanical
  Engineering
• Ph.D. in Mechanical Engineering
• _at_ University of California at Berkeley, CA
• M.S. and B.S. in Mechanical Engineering
• _at_ National Taiwan University, Taipei, Taiwan
• Working on using lasers to ablate germanium and
  copper and condense them together to form a
  nanoparticle core-shell material that has
  superior optical and electromagnetic properties.

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If you will recall, our project.

• Uses 2 lasers to ablate a germanium and copper
  sample a fraction of a second apart
• The second material (copper) condenses onto first
  (germanium) to form core-shell particle
• Particles deposit over time and are sent to a SEM
  and/or a TEM for imaging
• If the particle is a core-shell particleparty.
  then determine the properties of it.

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What could my class do to cover the TEKS and
touch on some of the cool stuff weve done in the
laboratory?
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The main ideas that our research project touched
on were

• Using lasers
• Creation of nanoparticles
• Experimental design
• Energy conversions and thermal expansion

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So, after MUCH deliberation.

• I decided to use laser light and
  having the students design a project!
• Why?
• -Most realistic costs- after many hours pricing
  items from internet
• -Most concepts for kids to learn within the
  physics TEKS
• -Topic with the most design ideas

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Physics TEKS Project Will Cover

• (8)  Science concepts. The student knows the
  characteristics and behavior of waves. The
  student is expected to
• (A)  examine and describe a variety of waves
  propagated in various types of media and describe
  wave characteristics such as velocity, frequency,
  amplitude, and behaviors such as reflection,
  refraction, and interference
• (B)  identify the characteristics and behaviors
  of sound and electromagnetic waves and
• (C)  interpret the role of wave characteristics
  and behaviors found in medicinal and industrial
  applications.

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Or, the recently revised Physics TEKS

• (7) Science concepts. The student knows the
  characteristics and behavior of waves. The
  student is expected to
• (A) examine and describe oscillatory motion and
  wave propagation in various types of media
• (B) investigate and analyze characteristics of
  waves, including velocity, frequency, amplitude,
  and wavelength, and calculate using the
  relationship between wave speed, frequency, and
  wavelength
• (C) compare characteristics and behaviors of
  transverse waves, including electromagnetic waves
  and the electromagnetic spectrum, and
  characteristics and behaviors of longitudinal
  waves, including sound waves
• (D) investigate behaviors of waves, including
  reflection, refraction, diffraction,
  interference, resonance, and the Doppler effect
• (E) describe and predict image formation as a
  consequence of reflection from a plane mirror and
  refraction through a thin convex lens and
• (F) describe the role of wave characteristics and
  behaviors in medical and industrial applications.

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Focused L.A.S.E.R.s are used in.(AKA
Mrs....why are we doing this?)

• Besides the fact that its cool
• DVD and CD players
• LASIK eye surgery
• Metal working
• Etching
• Weaponry
• Microscopes
• Alignment
• Ablation
• And much, much more!

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Safety First!

• Today, it is accepted that even low-power lasers
  with only a few milliwatts of output power can be
  hazardous to human eyesight, when the beam from
  such a laser hits the eye directly or after
  reflection from a shiny surface. At wavelengths
  which the cornea and the lens can focus well, the
  coherence and low divergence of laser light means
  that it can be focused by the eye into an
  extremely small spot on the retina, resulting in
  localized burning and permanent damage in seconds
  or even less time.
• Students will be signing a safety contract
  designed for this project. (Even though our
  lasers arent high powered.)

http//en.wikipedia.org/wiki/Laser
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What will the kids be doing?

• Their project sheet states the following

tentative
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What will we be using? A 7 beam laser
box (have ordered 2) A light meter -measures
lux (ordered 1 so far) -possibly probeware,
depending on what the school can do.
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We will also be using.

• 6 Mirrors 6 Lenses

http//www.surplusshed.com/pages/item/l1875d.html
http//www.christianbook.com/Christian/Books/overs
ize?sku754037
...different shapes and sizes of mirrors/lenses
for purpose of discovering which works best for
their challenge activity
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How will they be scored?
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Example project
1 (57.5)
2 (52.5)
3 (34.2)
4 (33.3)

• This project has 4 segments, the beam covers
  177.5 cm (1.775m) and has 33 of the original
  intensity.

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How would I calculate my score?

• S N L (I)2
• n (i)2
• S 4.0 1.775m(.33)2
• 1 ( 1 )2
• S 4.0 1.775 0.11 0.78
• I bet they can do much better than this! ?

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Other scores obtained on mission

• Schematic DrawingYou will need to draw a
  schematic of your design that is to scale. You
  may pick the scale (12, 110, 150, etc). When
  you draw a schematic, you should include as many
  dimensions as possible to give NASA an idea of
  how to duplicate your project. See classroom
  example and rubric for help.
• Team Interview and Presentation
• You will need to know about all parts of your
  project for a brief presentation and team
  interview. You will explain how your project is
  solving the problem. The interview is very
  brief, and consists of why and how type
  questions.
• Journal of Design Process
• You will need to keep a ledger of your design
  process, good/bad ideas our group had, who did
  what, etc. The more detail you include, the
  better your grade- so be thorough. You will also
  answer some questions given in class here as
  well.

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Pre-Test/Post-Test
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Pre-Test/Post-Test
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Project Timeline

• Day 1 Pre-Test 25 min
• Safety Lesson 10 min
• Q difference between sci. engr.? 10 min
• Day 2 Engineering design lesson 20 min
• Assign project and groups of 3-4 20 min
• Journaling questions 10 min
• Day 3 Vocabulary and demos 15 min
• Student design time 30 min
• During warm-ups and class time- journaling will
  occur.

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Project Timeline

• Day 4 Student ocular discovery activity online
  15 min
• http//www.glencoe.com/sites/common_asset
  s/science/virtual_labs/E11/E11.html
• Student design time with supplies 30
  min
• Day 5 Trials and redesign 45 min
• Day 6 Final test and calculations 45 min
• Day 7 Present projects 5 min each group x 10
• Day 8 Post-Test 25 min (catch-up time if
  needed 20 min)
• During warm-ups and class time- journaling will
  occur.

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Journaling (Interactive Notebook)

• Inventors, engineers, naturalists, and
  scientists all keep written records of their
  work!
• What is difference between science and
• engineering?
• Class info, notes, etc.
• Engineering design flowchart
• Results and discoveries
• Vocabulary, concept maps
• Targets type B kids

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Any Questions?
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Acknowledgements

• Texas AM
• National Science Foundation
• E3 RET Program coordinators
• Mechanical Engineering Dept
• Dr Sy-Bor Wen and his team
• And viewers like you