Introduction to Nanotechnology: Overview and Introduction to Nanotechnology: What, Why and How Mark Tuominen Professor of Physics Jonathan Rothstein Professor of Mechanical Eng.

NSF Center for Hierarchical Manufacturing "NSEC" NSF Center for Hierarchical Manufacturing A Center on Nanomanufacturing at UMass Research Education Outreach

The biggest science initiative since the Apollo program Nanotechnology The biggest science initiative since the Apollo program

1 nanometer = 1 billionth of a meter 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 DNA 6,000 nanometers Hair . 100,000 nanometers 10 nm objects made by guided self-assembly . 100,000 nanometers

Quantum corral of 48 iron atoms on copper surface The Scale of Things – Nanometers and More Things Natural Things Manmade 1 cm 10 mm Ant ~ 5 mm 10-2 m Head of a pin 1-2 mm Dust mite 200 mm The Challenge 1,000,000 nanometers = 10-3 m 1 millimeter (mm) MicroElectroMechanical (MEMS) devices 10 -100 mm wide Fly ash ~ 10-20 mm Microwave 10-4 m 0.1 mm 100 mm Human hair ~ 60-120 mm wide Microworld 10-5 m 0.01 mm 10 mm Pollen grain Infrared Red blood cells Red blood cells (~7-8 mm) 1,000 nanometers = Zone plate x-ray “lens” Outer ring spacing ~35 nm 10-6 m 1 micrometer (mm) Visible Fabricate and combine nanoscale building blocks to make useful devices, e.g., a photosynthetic reaction center with integral semiconductor storage. 0.1 mm 100 nm 10-7 m Ultraviolet Self-assembled, Nature-inspired structure Many 10s of nm Nanoworld 10-8 m 0.01 mm 10 nm ~10 nm diameter Nanotube electrode ATP synthase DNA ~2-1/2 nm diameter Atoms of silicon spacing 0.078 nm 10-9 m 1 nanometer (nm) Carbon buckyball ~1 nm diameter Soft x-ray Carbon nanotube ~1.3 nm diameter 10-10 m 0.1 nm Quantum corral of 48 iron atoms on copper surface positioned one at a time with an STM tip Corral diameter 14 nm Office of Basic Energy Sciences Office of Science, U.S. DOE Version 05-26-06, pmd

Applications of Nanotechnology

First, One Example: iPod Data Storage Capacity 10 GB 2001 20 GB 2002 40 GB 2004 80 GB 2006 160 GB 2007 Hard drive Magnetic data storage Uses nanotechnology!

Hard Disk Drives - a home for bits Hitachi

Magnetic Data Storage A computer hard drive stores your data magnetically “Read” Head Signal “Write” Head current magnets S N Disk N S 1 _ “Bits” of information direction of disk motion

Improving Magnetic Data Storage Technology The UMass Amherst Center for Hierarchical Manufacturing is working to improve this technology Granular Media Perpendicular Write Head Soft Magnetic UnderLayer (SUL) coil 1 bit Y. Sonobe, et al., JMMM (2006) • CHM Goal: Make "perfect" media using self-assembled nano-templates • Also, making new designs for storage

Applications of Nanotechnology Since the 1980's electronics has been a leading commercial driver for nanotechnology R&D, but other areas (materials, biotech, energy, and others) are of significant and growing importance. Some applications of nanotechnology has been around for a very long time already: Stained glass windows (Venice, Italy) - gold nanoparticles Photographic film - silver nanoparticles Tires - carbon black nanoparticles Catalytic converters - nanoscale coatings of platinum and palladium

Why do we want to make things at the nanoscale? To make better products: smaller, cheaper, faster and more effective. (Electronics, catalysts, water purification, solar cells, coatings, medical diagnostics & therapy, and more -- a sustainable future!) To discover completely new physical phenomena to science and technology. (Quantum behavior and other effects.)

The National Nanotechnology Initiative nano.gov - the website of the NNI

Types of Nanostructures and How They Are Made

"Nanostructures" Nanoscale Devices and Systems Nano-objects Nanostructured Materials "nanorod" "nanoparticle" "nanofilm" "nanotube" and more nanoscale outer dimensions nanoscale internal structure Integrated nano-objects and materials

Making Nanostructures: Nanomanufacturing "Top down" versus "bottom up" methods Lithography Deposition Etching Machining Chemical Self-Assembly

Some nanomaterials are just alternate arrangements of well-known materials Carbon materials diamond graphite 2010 Nobel Prize! C60 graphene carbon nanotubes 20

Nanofilms Nanofilm on glass Nanofilm on plastic Gold-coated plastic for insulation purposes "Low-E" windows: a thin metal layer on glass: blocks UV and IR light

A nanofilm method: Thermal Evaporation sample QCM Vaporization or sublimation of a heated material onto a substrate in a vacuum chamber film vapor Au, Cr, Al, Ag, Cu, SiO, others Pressure is held low to prevent contamination! vacuum ~10-7 torr source There are many other thin film manufacturing techniques heating source vacuum pump

Patterning: Photolithography process recipe apply spin bake spin coating substrate spin on resist resist expose mask (reticle) exposed unexposed "scission" narrow line narrow trench develop liftoff etch deposit

Patterning: Imprint Lithography Thermal Imprint Lithography Emboss pattern into thermoplastic or thermoset with heating UV-Assisted Imprint Lithography Curing polymer while in contact with hard, transparent mold Mold Template Polymer or Prepolymer Substrate Imprint Pressure Heat or Cure Release

Limits of Lithography IBM - Copper Wiring On a Computer Chip Complex devices need to be patterned several times Takes time and is expensive Limited by wavelength of light Deep UV ~ 30nm features Can use electrons instead 1nm features possible MUCH slower than optical IBM - Copper Wiring On a Computer Chip

Self Assembly

An Early Nanotechnologist?

Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov ...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 saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and 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 Glass.... A nanofilm!

"Quantum Dots" by Chemical Synthesis (reverse-micelle method) "Synthesis and Characterization of Nearly Monodisperse Semiconductor Nanocrystallites," C. Murray, D. Norris, and M. Bawendi, J. Am. Chem. Soc. 115, 8706 (1993) Color is determined by particle size!

Interaction with Light E = hf a 420 THz 750 THz "Artificial atom" Many applications: solar cells, biomarkers, lighting, and more!

SELF ASSEMBLY with DIBLOCK COPOLYMERS Block “B” Block “A” PS PMMA ~10 nm Scale set by molecular size Ordered Phases 10% A 30% A 50% A 70% A 90% A

Versatile, self-assembling, nanoscale lithographic system CORE CONCEPT FOR NANOFABRICATION Deposition Template Etching Mask Nanoporous Membrane (physical or electrochemical) Remove polymer block within cylinders (expose and develop) Versatile, self-assembling, nanoscale lithographic system

Nanomagnets in a Self-Assembled Polymer Mask nanoporous template 1x1012 magnets/in2 Pulse reverse electrodeposition results in improved microcrystalline structure and improved magnetic properties (larger perpendicula magnetocrystalline anisotropy) Data Storage... ...and More

More Applications of Nanotechnology

Solar Cells Benefit: Sun is an unlimited source of electronic energy. Konarka

Electric Solar Cells Sunlight - - - - -- - - - + 0.5 Volt p-n junction interface Sunlight - cross-sectional view “load” - - - -- - - - n-type silicon 0.5 Volt + + + ++ + + + Voltage p-type silicon + The electric power produced is proportional to the area of the solar cell Current

Nanostructured Solar Cells Sunlight - “load” Voltage + Current More interface area - More power!

Nanomedicine: Cancer Therapy targeted therapy: hyperthermic treatment tumor gold nanoshells Halas group, Rice Univ. www.sciencentral.com/articles/view.php3?article_id=218392390 www.nano.gov/html/news/SpecialPapers/Cancer

Nanotechnology is an example of The Medici Effect at work People from diverse fields working together -- more rapidly solving important problems in our society Physics Chemistry Biology Materials Science Polymer Science Electrical Engineering Chemical Engineering Mechanical Engineering Medicine And others Electronics Materials Health/Biotech Chemical Environmental Energy Food Aerospace Automotive Security Forest products

Cooperation and Collaboration Across Professions Makes It Happen Cooperation of academia, industry, and government to advance science and technology Example: America Competes Act (Dec. 2010) - Nanotechnology and Education play key roles Example: American Manufacturing Partnership (June 2011) Education + Science + Engineering + Business + Policy + More 40

A Message for Students Nanotechnology is changing practically every part of our lives. It is a field for people who want to solve technological challenges facing societies across the world