Overview and Introduction to Nanotechnology: What, Why and How 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 ResearchEducationOutreach A Center on Nanomanufacturing at UMass

Nanotechnology The biggest science initiative since the Apollo program

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 m nano.gov

How small are nanostructures? Single Hair Width = 0.1 mm = 100 micrometers = 100,000 nanometers !

Smaller still Hair. DNA 3 nanometers 6,000 nanometers 100,000 nanometers 10 nm objects made by guided self-assembly

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

Applications of Nanotechnology

10 GB GB GB GB GB 2007 First, An Example: iPod Data Storage Capacity 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 Disk NS direction of disk motion Write Head __ Bits of information NS Read Head Signal current

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 Y. Sonobe, et al., JMMM (2006) 1 bit CHM Goal: Make "perfect" media using self-assembled nano-templates Also, making new designs for storage

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 Applications of Nanotechnology

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) To introduce completely new physical phenomena to science and technology. (Quantum behavior and other effects.) For a sustainable future!

"Biggest science initiative since the Apollo program"

Types of Nanostructures and How They Are Made

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

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

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

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

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

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

Limits of Lithography 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. 7, 1773)...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!

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

a Interaction with Light "Artificial atom" E = hf 420 THz750 THz

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 Scale set by molecular size

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

nanoporous template Nanomagnets in a Self-Assembled Polymer Mask 1x10 12 magnets/in 2 Data Storage......and More

More Applications of Nanotechnology

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

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

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

Nanomedicine: Cancer Therapy tumor gold nanoshells Halas group, Rice Univ. targeted therapy: hyperthermic treatment

Perhaps the most important result in nanotechology so far: People from diverse fields working together to solve 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

Communication Between Scientists and Government Leaders is Important Nanomanufacturing impacts jobs, economic security, intellectual progress and sustainability Immediate need for more robust: workforce training nanomanufacturing test beds and pilot projects process and tool development nanoinformatics standards development PCAST recommends: "Increase NNI funding for nanomanufacturing research while maintaining support for basic research"

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