Presentation on theme: "Introduction to Nanotechnology: What, Why and How Mark Tuominen, UMass, November 17, 2007 bnl manchester."— Presentation transcript:
Introduction to Nanotechnology: What, Why and How Mark Tuominen, UMass, November 17, 2007 bnl manchester
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 ! 1 nanometer = one billionth (10 -9 ) meter
Smaller still Hair. Red blood cell 6,000 nanometers DNA 3 nanometers
A Few Nanostructures Made at UMass 100 nm dots 70 nm nanowires200 nm rings 12 nm pores14 nm dots 13 nm rings25 nm honeycomb 14 nm nanowires 18 nm pores 150 nm holes
10 GB GB GB GB GB 2007 Example: Advancement of the iPod Hard drive Magnetic data storage Uses nanotechnology!
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
Scaling Down to the Nanoscale Increases the amount of data stored on a fixed amount of real estate ! Now ~ 100 billion bits/in 2, future target more than 1 trillion bits/in 2 25 DVDs on a disk the size of a quarter, or all Library of Congress books on a 1 sq ft tile!
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.)
Nanotech: How? How to make nanostructures? How to characterize and test them?
Making Nanostructures: Nanofabrication Top down versus bottom up methods Lithography Deposition Etching Machining Chemical Self-Assembly
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....
... the Oil tho' not more than a Tea Spoonful perhaps half an Acre CHALLENGE: How thick was the film of oil? Volume = (Area)(Thickness) V = A t V = 1 teaspoonful A = 0.5 acre ~ 2 cm 3 ~ 2,000 m 2 t = V/A 20,000,000 cm 2 = 2 cm 3 20,000,000 cm 2 = cm = 1 x cm = 1 x m = 1 nanometer (nm)
A monolayer NANOFILM (single layer of molecules) ~1 nm thick Langmuir film An example of a FILM This is an example of SELF-ASSEMBLY
Langmuir-Blodgett Film Must control movable barrier to keep constant pressure multiple dips - multiple layers
Another 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 resistive, e-beam, rf or laser heat source Pressure must be held low to prevent contamination! Au, Cr, Al, Ag, Cu, SiO, others There are many other thin film manufacturing techniques
Nanofilm by Electroplating V I Cu e - –> Cu (0) "reduction" CuSO 4 dissolved in water Cu (0) –> Cu e - "oxidation" anodecathode If using an inert Pt electrode: 2 H 2 O –> O 2 + 4H + + 4e - Working Electrode (WE) Counter Electrode (CE)
Imaging Nanostructures Atomic Force Microscope (AFM)
. "Optical Lever" for Profilometry cantilever laser
. "Optical Lever" for Profilometry cantilever laser Long light path and a short cantilever gives large amplification
Atomic Force Microscope AFM Cantilever Chip AFM Instrument Head Laser Beam PathCantilever Deflection
Image of Nickel Atoms STM
Lithography (controlling width and depth)
Lithography Mark Tuominen Mark Tuominen Mark Tuominen (Using a stencil or mask)
Photolithography for Deposition substrate process recipe spin on resist resist expose mask (reticle) develop deposit liftoff narrow line applyspinbake spin coating exposed unexposed "scission"
Lithography IBM Copper Wiring On a Computer Chip Patterned Several Times
Electron-Beam Lithography Silicon crystal Polymer film Electron Beam Nanoscopic Mask !
Self-Assembled Nanostructures and Lithography Based on Self-Assembly
Diatoms priweb.org sinancanan.net
NANOFABRICATION BY SELF ASSEMBLY 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 Diblock Copolymers
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)
Application examples: Nanoelectronics
Computer Microprocessor "Heart of the computer" Does the "thinking"
Making Small Smaller An Example: Electronics-Microprocessors ibm.com macroscale microscale nanoscale
Electronics Keep On Getting Better Moore's "Law": Number of Transistors per Microprocessor Chip intel.com
Hard Disk Drives - a home for bits Hitachi
Magnetic Data Storage ? Magnet with unknown magnetic state Current N S 0 S N 1 N S S N
Binary Representation of Data one bit1 or 0 only 2 choices two bits00, 01, 10, 11 4 choices three bits 000, 001, 010, 011, 100, 101, 110, choices n bits has 2 n choices For example, 5 bits has 2 5 = 32 choices... more than enough to represent all the letters of the alphabet
Binary representation of lower case letters 5-bit "Super Scientist" code: ex: k = S N S N S N N S N S OR (Coding Activity: Use attractive and repulsive forces to "read" the magnetic data!)
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
nanoporous template nanowires in a diblock copolymer template Electrodeposited Nanowires in a Nanoporous Polymer Template (Mask) 1x10 12 wires/in 2
Benefit: Sun is an unlimited source of electronic energy. Solar Cells Konarka
Electric Solar Cells Made from single-crystal silicon wafers (conventionally) cross-sectional view n-type silicon p-type silicon + - Sunlight Voltage load + - Current The load can be a lamp, an electric motor, a CD player, a toaster, etc wires
Nanostructured Solar Cells + - Sunlight Voltage load Current More interface area - More power!
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
Thanks for visiting UMass and learning about nanotechnology!