NanotechnologyWhat, How, Why?

MAST, October 22, 2010

Brought to you by …

• NSF grant DMI-0531171 to the UMass Amherst Center for Hierarchical Manufacturing

• Mort Sternheim, Director, STEM Education Institute, mort@umassk12.net

• Rob Snyder, STEM Ed, snyder@umassk12.net

• www.umassk12.net/nano

Today’s Agenda

• Introduction – Mort Sternheim

• Make a nanofilm – Rob Snyder– Was Franklin the first nanotechnologist?

Nanotechnology Summer Institute

• Monday to Friday, June 27-July 1, 2011 UMass Amherst • Middle and High School Science, Math, and Technology

Teachers; Informal Educators (from anywhere)• $75/day stipends ($375 total), materials, parking,

lunches • Housing (new air conditioned dorms) and meals for

those outside the commuting radius• 3 graduate credits available at reduced cost; free PDP's

(Professional Development Points) • Also available: STEM DIGITAL Institute July 12-16• See flyer

What: Nanotechnology

Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.

1 nanometer = 1 billionth of a meter= 1 x 10-9 m

nano.gov

How small are nanostructures?

Single Hair

Width = 0.1 mm

= 100 micrometers

= 100,000 nanometers !

Smaller still

Hair

.

Red blood cell

6,000 nanometersDNA

3 nanometers

Relative sizes

• Atomic nuclei ~ 10-15 meters = 10-6 nanometers

• Atoms ~ 10-10 meters = 0.1 nanometers• Nanoscale ~ 1 to 100 nanometers

~ 10 to 1000 atoms• Everyday world ~ 1 meter

= 109 nanometers • More on powers of ten on our website,

others

How: MakingNanostructures

Making Nanostructures: Nanomanufacturing

"Top down" versus "bottom up" methods

•Lithography•Deposition•Etching•Machining

•Chemical•Self-Assembly

Self Assembly

SELF ASSEMBLY with DIBLOCK COPOLYMERS

Block “A” Block “B”

10% A 30% A 50% A 70% A 90% A

~10 nm

Ordered Phases

PMMA PS

Phase separation...on the nanoscale

Self-AssembledNanoscale "Stencils" Deposition

Template

EtchingMask

NanoporousMembrane

Remove polymerblock within cylinders(expose and develop)

A self-assembling, nanoscale lithographic system

(physical orelectrochemical)

Why: Applications

Why do we want to make things at the nanoscale?

• To make better and new products: smaller, cheaper, faster and more effective. (Electronics, catalysts, water purification, solar cells, coatings, medical diagnostics & therapy, etc)

• To introduce completely new physical phenomena to science, technology. (Quantum behavior and other effects.)

http://www.masspolicy.org/pdf/workshop/rejeski.pdf

10 GB2001

20 GB2002

40 GB2004

80 GB2006

160 GB2007

Example: Data storage capacity of the iPod

Hard driveMagnetic data storage

Uses nanotechnology!Nanomagnets!

Scaling Down to the Nanoscale

Increases the amount of data stored on a fixed amount of “real estate” !

Now ~ 100 billion bits/in2, future target more than 1 trillion bits/in2

25 DVDs on a disk the size of a quarter, orall Library of Congress books on a 1 sq ft tile!

Solar Cells

Konarka

Benefit: Sun is an unlimited source of electronic energy.

Nanostructured Solar Cells

+

-

Sunlight

Voltage “load”

CurrentMore interface area - More power!

Targeted Cancer Therapy

Cancer Therapy

tumor

gold nanoshells

Naomi Halas group, Rice Univ.

www.sciencentral.com/articles/view.php3?article_id=218392390

targeted therapy: hyperthermic treatment

Nanoshells are coated with a substance that binds them to cancer cells. Absorb IR and destroy cancer cells with heat; no harm to healthy cells

More Applications

• Sunscreens with nanoparticles to block UVA– Earlier sunscreens only block UVB; UVA and

UVB both cause cancer• Water purification with nanofilters• http://nanosense.org/ - sunscreen and nanofilters

• Stain resistant fabrics

• Better Kelvar bullet proof vests

Nanotechnology R&D is interdisciplinary and impacts many applications

• Physics• Chemistry• Biology• Materials Science• Polymer Science• Electrical Engineering• Chemical Engineering• Mechanical Engineering• Medicine• And others

• Electronics• Materials• Health/Biotech• Chemical• Environmental• Energy• Aerospace• Automotive• Security• Forest products• And others

Nanoscale Thin FilmsNanoscale Thin Films

Today’s AgendaToday’s Agenda

• Ben Franklin’s ObservationBen Franklin’s Observation

• Interactions between Oleic Acid and Interactions between Oleic Acid and WaterWater

• Create a thin film of oleic acidCreate a thin film of oleic acid

• Calculate the thickness of the thin film Calculate the thickness of the thin film of oleic acidof oleic acid

Was Ben Franklin an Early NanoscientistWas Ben Franklin an Early Nanoscientist??

Excerpt from Letter of Benjamin Franklin to William Brownrigg (Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773) Nov. 7, 1773)

...At length being at Clapham, where there is, on the Common, a large ...At length being at Clapham, where there is, on the Common, a large Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface ... the Oil saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and tho' not more than a Tea Spoonful ... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....Glass....

... the Oil tho' not more than a Tea Spoonful ...

... perhaps half an Acre

CHALLENGE: How thick was the film of Ben Franklin’s oil?

Volume = (Area)(Thickness)

V = A T

V = 1 teaspoonful

A = 0.5 acre

~ 2 cm3

~ 2,000 m2

T = V/A

20,000,000 cm2

T = 2 cm3

20,000,000 cm2

T = 0.0000001 cm T = 1 x 10-7 cm T = 1 x 10-9 m T = 1 nanometer

It would be difficult to conduct a thin film It would be difficult to conduct a thin film experiment on the UMass Amherst experiment on the UMass Amherst

campus pond.campus pond.

A plastic tray can be used to A plastic tray can be used to experiment with thin films.experiment with thin films.

However, you need to use much less However, you need to use much less than a teaspoon of oil.than a teaspoon of oil.

You will form a thin film on the surface of You will form a thin film on the surface of water using a small amount of one of water using a small amount of one of

olive oil’s ingredients.olive oil’s ingredients.

That ingredient is oleic acid. That ingredient is oleic acid. The polar end of oleic acid molecules are The polar end of oleic acid molecules are attracted to polar water molecules.attracted to polar water molecules.

When you pour a very small amount of oleic acid When you pour a very small amount of oleic acid onto the surface of water, the oleic acid molecules can onto the surface of water, the oleic acid molecules can “self-assemble” into a thin layer.“self-assemble” into a thin layer.

In a small drop of oleic acid there are billions of In a small drop of oleic acid there are billions of oleic acid molecules that will stand up like oleic acid molecules that will stand up like

blades of grass on the surface of waterblades of grass on the surface of water.

The thin film of oleic acid forms a Langmuir The thin film of oleic acid forms a Langmuir Film. The thin film can be confined to a Film. The thin film can be confined to a specific area with a barrier. You will use small specific area with a barrier. You will use small particles as a confining barrier.particles as a confining barrier.

water

hydrophobic end

hydrophilic end

Now its your turn to create a thin Now its your turn to create a thin layer on the surface of water.layer on the surface of water.

• Water is in each plastic tray. Water is in each plastic tray. • Make a very dilute solution of oleic acid in alcohol.Make a very dilute solution of oleic acid in alcohol.• Determine how many drops of a very dilute solution Determine how many drops of a very dilute solution

are in one cmare in one cm33 of the very dilute solution. of the very dilute solution.• Evenly sprinkle a layer of baby powder across the Evenly sprinkle a layer of baby powder across the

surface of the water.surface of the water.• Let one drop of the very dilute solution of oleic acid Let one drop of the very dilute solution of oleic acid

spread across the surface of the water. spread across the surface of the water. • The alcohol solvent will dissolve in water leaving a The alcohol solvent will dissolve in water leaving a

thin film of oleic acid solute on the surfacethin film of oleic acid solute on the surface• Measure the average diameter of the circular layer of Measure the average diameter of the circular layer of

oleic acid.oleic acid.

A Sample Calculation of the volume of A Sample Calculation of the volume of oleic acid in just one drop of the second oleic acid in just one drop of the second dilute solutiondilute solution

The following steps correspond to the sequence of The following steps correspond to the sequence of calculations on your calculation worksheet.calculations on your calculation worksheet.

Step 1: The volume fraction = 1 / 25Step 1: The volume fraction = 1 / 25

Step 2: 0.04 cmStep 2: 0.04 cm33

Step 3: 0.04 cmStep 3: 0.04 cm33 / 25 = 0.0016 cm / 25 = 0.0016 cm33

Step 4: A group determined that 40 drops of the Step 4: A group determined that 40 drops of the second dilute solution = 1.0 cmsecond dilute solution = 1.0 cm33..

Step 5: If a group determined that 40 drops of the Step 5: If a group determined that 40 drops of the second solution of oleic acid had a volume of 1.0 second solution of oleic acid had a volume of 1.0 cmcm33; Then 0.0016 cm; Then 0.0016 cm33 / 40 = 0.00004 cm / 40 = 0.00004 cm33..

A sample calculation of the A sample calculation of the thickness of the oleic acid filmthickness of the oleic acid film

Step 6: If a group estimated that average diameter Step 6: If a group estimated that average diameter their thin film of oleic acid was 14.50 cm, then the their thin film of oleic acid was 14.50 cm, then the average radius is 7.25 cm.average radius is 7.25 cm.

Step 7: Area = 3.14 x RStep 7: Area = 3.14 x R22 For example: The area of For example: The area of that thin film was 165.05 cmthat thin film was 165.05 cm22

Step 8: Step 8: If Volume = Area x Depth; If Volume = Area x Depth; Then: Depth = Volume / Area and the thickness of Then: Depth = Volume / Area and the thickness of

the example group’s film would be 2.42 x 10the example group’s film would be 2.42 x 10-7-7 cm. cm.

Step 9: 2.42 x 10Step 9: 2.42 x 10-7-7 cm = 2.42 x 10 cm = 2.42 x 10-9-9 m = 2.42 m = 2.42 nanometersnanometers

A Few QuestionsA Few Questions What might be some sources of error What might be some sources of error

when calculating the thickness of a layer when calculating the thickness of a layer of oleic acid?of oleic acid?

How could the sources of error be How could the sources of error be minimized?minimized?

What would be some challenges when What would be some challenges when using a tray the size of a dinner plate?using a tray the size of a dinner plate?

The Big Ideas in Self-AssemblyThe Big Ideas in Self-Assembly• Structural components are mobile. Structural components are mobile. • The goal is a low energy equilibrium state.The goal is a low energy equilibrium state.• Ordered structures result from a less ordered Ordered structures result from a less ordered

system.system.• Assembly is a result of attractive or repulsive Assembly is a result of attractive or repulsive

forces between the components.forces between the components.• An environment is selected to induce An environment is selected to induce

designed interaction.designed interaction.• Components retain physical identity through Components retain physical identity through

and after.and after.

• The process is reversible or adjustableThe process is reversible or adjustable..Whitesides & Boncheva (2002)

Nanotechnology Summer Institute

• Monday to Friday, June 27-July 1, 2011 UMass Amherst • Middle and High School Science, Math, and Technology

Teachers; Informal Educators (from anywhere)• $75/day stipends ($375 total), materials, parking,

lunches • Housing (new air conditioned dorms) and meals for

those outside the commuting radius• 3 graduate credits available at reduced cost; free PDP's

(Professional Development Points) • Also available: STEM DIGITAL Institute July 12-16• See flyer