december 4, 2014 what’s nano about light?. today’s plan introduce the international year of...

December 4, 2014

What’s Nano about Light?

Today’s Plan

• Introduce the International Year of Light

(IYL)

• Discuss possible partners for IYL

• Present NISE resources for IYL

• Describe the science behind two NanoDays

activities

• If time, a surprise!

2

International Year of Light (IYL)

“A global initiative adopted by the United Nations to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in energy, education, agriculture, communications and health.”

“The science and applications of light creates revolutionary - but often unseen - technologies that directly improve quality of life worldwide.”

3http://www.light2015.org/

CommunicationsHealth Economy Environment Social

Celebrating Light

4SPIE, http://www.youtube.com/watch?v=rcoMeWV0jZc

What’s Nano about Light?

5

Stained glass(metallic nanoparticles)

Medicine (nanoparticles, nano-coatings)

Electronics(nanostructures like thin films)

Energy(nanostructures)

SPIE, http://www.youtube.com/watch?v=rcoMeWV0jZc

Why Should You Care About the IYL?

• Kids are naturally interested in light and color

• This is a great opportunity for partnering with scientists

• There are tons of great NISE resources (activities and videos) related to light

6

Check-in Time

(1)Are you interested in trying to bring in scientists for IYL events?

(2)Do you already know scientists you could contact?

7

IYL Partner Organizations

8http://www.light2015.org/

Finding a Partner

• IYL is a great time to approach scientists, because they’re supposed to be involved in outreach

• What kinds of scientists/organizations are involved in IYL?

• NISE has contacts in SPIE and OSA

9

• Physicists• Material scientists/engineers• Electrical engineers• Optical engineers

• SPIE (physicists/engineers)• APS (physicists)• OSA (physicists and engineers)• IEEE (engineers)

APS = American Physical Society, OSA = Optical Society of America, IEEE = Institute of Electrical and Electronics Engineers

Check-in Time

Any general questions about the International Year of Lightor finding scientist partners?

10

Light-related Resources from NISE

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NanoDays activities

Videos

Programs

http://www.nisenet.org/events/other/international-year-light-2015

So many great resources!

Light-Related ActivitiesMany of these activities aren’t just related to light—they’re also an excellent introduction to everything that’s cool and unique about nano

12

Light-related Topics: Examples• Light in nature

• Butterfly• Thin Films• Bubbles

• Nanoscale-phenomena• Sunblock• Nano Gold• Invisibility

• New technologies/devices• Liquid crystal displays• Thin Films 13

http://www.nisenet.org/

Light-Related Videos

14

http://vimeo.com/31270439

Nano and Me - Gold

http://vimeo.com/74400132

What’s Nano About Bubbles?

http://www.nisenet.org/

Check-in Time

(1)Do you have a favorite light-related activity from NISE? If so, what is it?

15

Check-in Time

(1)Do you have a favorite light-related activity from NISE? If so, what is it?

(2)Do you find it challenging to describe the science behind any of NISE’s light-related activities? If so, which one(s)?

16

Absorption, Reflection, and Transmission

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• Sunlight and other white light contains all colors

• When light hits an object, it can be• Absorbed• Reflected• Transmitted

• In the case of raspberries• Green and blue are strongly

absorbed• Red is only partially absorbed

Absorption, Reflection, and Transmission

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Absorption + Reflection + Transmission = 100%

http://design.tutsplus.com/tutorials/draw-a-shiny-make-up-mirror-with-adobe-illustrator--vector-4418

Check-in Time

Why does a red apple look red?

(1)It absorbs most of the red light from the sun

(2)It reflects most of the red light from the sun

(3)It transmits most of the red light from the sun

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Why does a red apple look red?

(1)It absorbs most of the red light from the sun

(2)It reflects most of the red light from the sun

(3)It transmits most of the red light from the sun

20

The color of an object is not actually within the object itself. Rather, the color is in the light that shines upon it and is ultimately reflected or transmitted to our eyes. [http://www.physicsclassroom.com]

Learn more here: http://www.physicsclassroom.com/class/light/Lesson-2/Color-Subtraction

Nano Gold (Stained Glass)

21http://design.tutsplus.com/tutorials/draw-a-shiny-make-up-mirror-with-adobe-illustrator--vector-4418

Bulk vs Nano Gold

22

Nano Gold

Bulk Gold

http://education.mrsec.wisc.edu/nanolab/gold_uv/index.html#Introduction

Stained glass

Size and Shape Matter

23http://www.horiba.com/scientific/ http://commons.wikimedia.org/wiki/File:Native_gold_nuggets.jpghttp://www.cat.gov.in/technology/laser/lpas/pps.html

At the nanoscale,size matters!

At the nanoscale,shape matters, too!

How are the Colors Created?

24http://edcvs.co/130nfaU

Resonance Causes Absorption & Scattering

• Bells are a great analogy because they ring due to resonance (reverberation)• We usually think about resonance in terms of sound waves,

but other waves can also undergo resonance

• Metallic surfaces have surface plasmons – delocalized electrons

• These electrons have wave properties

25

Resonance Causes Absorption & Scattering

• Light of a specific wavelength can interact strongly with these delocalized electrons, making them resonate

• We call this surface plasmon resonance

• Light that interacts strongly is absorbed and/or scattered; other wavelengths of light are mainly transmitted• Produces vibrant colors

• To learn more about scattering, read about how scattering causes the sky to look blue

26

Example: Lycurgus cupExample: Lycurgus cupExample: translucent red cupExample: translucent red cup

Color of Reflected vs Transmitted Light

27http://www.shutterstock.com/pic-177894944/stock-photo-group-of-colorful-pink-orange-and-yellow-translucent-plastic-party-cups-with-color-shadows.html

http://www.smithsonianmag.com/history/this-1600-year-old-goblet-shows-that-the-romans-were-nanotechnology-pioneers-787224/?no-ist

But nano gold and silver have different colors in reflected vs. transmitted light

Usually, reflected and transmitted colors are the same

Red light Reflected and transmitted

Green light Absorbed

Blue light Absorbed

Red light Transmitted

Green light Absorbed and scattered

Blue light Absorbed and scattered

Applications of Nano Gold

28https://vimeo.com/channels/nisenet/66928095

UV Bracelets

29http://design.tutsplus.com/tutorials/draw-a-shiny-make-up-mirror-with-adobe-illustrator--vector-4418

UV Beads

30

How UV Light Affects UV Beads

31http://www.profbunsen.com.au/files/uvdetectionbeads.pdf

• Originally beads are colorless because the molecules aren’t good at absorbing light

• UV light breaks bonds and changes the structure of the molecules

• This makes it possible for them to absorb light

UV light

UV Beads

• When not exposed to UV light, the molecules will convert back to their original forms, and beads will once again appear clear

• For older students, could investigate how temperature and other variables affect this process

32http://www.profbunsen.com.au/files/uvdetectionbeads.pdf

ShineUV light

Turn off UV light, then wait

Chemistry Behind Color

• How do pigment and dye molecules absorb light?• Certain wavelengths of light interact with electrons and

promote the electrons to a higher energy level

• These wavelengths (colors) are absorbed

33http://chemwiki.ucdavis.edu/Wikitexts/Prince_George's_Community_College/General_Chemistry_for_Engineering/Unit_1%3A__Atomic_Structure/Chapter_2%3A_Atomic_Structure/Chapter_2.3%3A_Atomic_Spectra_and_Models_of_the_Atom

UV Beads

34

High energy

Low energy

5 eV

Before UV exposure, energy gaps are larger

Visible light doesn’t have enough energy to promote an electron

UV Beads

35

High energy

Low energy

High energy

Low energy

5 eV

2.3 eV

Before UV exposure, energy gaps are larger

Visible light doesn’t have enough energy to promote an electron

After UV exposure, energy gaps are smaller

Certain colors of visible light have enough energy to promote electrons

[Orange bead]

A New Invisibility Demo!

36

Exploring Properties - Invisibility

http://nisenet.org/catalog/programs/exploring_properties_-_invisibility

Invisibility Cloak

http://nisenet.org/catalog/media/invisibility_cloak

Just in time for IYL, there’s a new invisibility (cloaking) demo you can try!

A New Invisibility Demo!

37

Just in time for IYL, there’s a new invisibility (cloaking) demo you can try!

http://www.rochester.edu/newscenter/

The “Rochester Cloak”

38

4 lenses, with some way to hold them up and align them

The “Rochester Cloak”

39http://www.rochester.edu/newscenter/

The “Rochester Cloak”

40

The “Rochester Cloak”

41

The “Rochester Cloak”

42

Fairly cheap, non-consummable materialsFun way to introduce cloakingPairs well with other NISE materials

Hard to keep lenses aligned (especially near a two-year-old!)May be hard to explain

Resources• Stained glass (nano gold)

• Good discussion of scattering: http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html

• UV beads

• Good discussion of pigments: http://hermes.mbl.edu/marine_org/images/animals/Limulus/vision/Wald/photosynthesis.html

• Guide from Educational Innovations: http://cdn.teachersource.com/downloads/lesson_pdf/UV-AST.pdf

• Inquiry-based activities

o http://www.carolina.com/teacher-resources/Interactive/activities-with-uv-beads/tr30403.tr

o http://www.carolina.com/teacher-resources/Document/students-plan-an-experiment-using-uv-beads/tr10866.tr

• Sunblock

• Great discussion of all the science behind nano sunblock; includes Powerpoint slides and lesson plans: http://nanosense.sri.com/activities/clearsunscreen/

• U. of Rochester cloaking demo

• Press release: http://www.rochester.edu/newscenter/watch-rochester-cloak-uses-ordinary-lenses-to-hide-objects-across-continuous-range-of-angles-70592/

• Published article: http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-22-24-29465%20

• This group has also developed another cloaking device that uses mirrors: https://www.youtube.com/watch?v=GAmWs6zfTj8 and https://www.youtube.com/watch?v=oJb9RnAVDuE 43

Sunblock

44http://design.tutsplus.com/tutorials/draw-a-shiny-make-up-mirror-with-adobe-illustrator--vector-4418

Sunscreens vs Sunblocks

45

• Sunscreens use chemicals

• There are also sunblocks that use minerals like zinc oxide or titanium dioxide

nisenet.org vitaderminstitute.com/

Sunscreens vs Sunblocks, Continued

46

How could sunscreen and sunblock work?

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

Absorption Reflection Transmission

Sunscreens vs Sunblocks, Continued

47

How could sunscreen and sunblock work?

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

SkinSkin

Sunscreen/SunblockSunscreen/Sunblock

Absorption Reflection Transmission

Sunscreens and sunblocks both usually work through absorption of UV raysSunblocks are better because they absorb more of the UV rays

Inorganic Sunblocks Absorb UV Better

48

UVB UVA visible

ideal

Nano Sunblocks

49http://www.tackletour.com/reviewbluelizard.html

Traditional zinc oxide sun blocks are very visible

Modern zinc oxide sun blocks are fairly invisible after application

Nano ZnO and TiO2 Reflect Less Light

50

UVB UVA visible

ideal