41 nanometer = 1 billionth of a meter NanotechnologyNanotechnology 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 mnano.gov
5How small are nanostructures? Single HairWidth = 0.1 mm= 100 micrometers= 100,000 nanometers !1 nanometer = one billionth (10-9) meter
8A Few Nanostructures Made at UMass 100 nm dots70 nm nanowires200 nm rings150 nm holes18 nm pores12 nm pores14 nm dots13 nm rings25 nm honeycomb14 nm nanowires
9"Nano" Nanoscale - at the 1-100 nm scale, roughly Nanostructure - an object that has nanoscale featuresNanoscience - the properties of nanostructures and the underlying scienceNanotechnology - the techniques for making and characterizing nanostructures and putting them to useNanomanufacturing - methods for producing nanostructures in reliable and commercially viable ways
11Example: Advancement of the iPod 10 GB200120 GB200240 GB200480 GB2006160 GB2007Hard driveMagnetic data storageUses nanotechnology!
12Magnetic Data StorageA computer hard drive stores your data magnetically“Read”HeadSignal“Write”HeadcurrentSNDiskNS1_“Bits” ofinformationdirection of disk motion
13Scaling Down to the Nanoscale Increases the amount of data storedon a fixed amount of “real estate” !Now ~ 100 billion bits/in2, future target more than 1 trillion bits/in225 DVDs on a disk the size of a quarter, orall Library of Congress books on a 1 sq ft tile!
14Why 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.)(More on why later)
15Nanotechnology: How? How to make nanostructures? How to characterize and test them?
16Making Nanostructures: Nanofabrication Top down versus bottom up methodsLithographyDepositionEtchingMachiningChemicalSelf-Assembly
19An example of a FILM: Oil on water A monolayer NANOFILM (single layer of molecules)~1 nm thickLangmuir filmThis is an example of SELF-ASSEMBLY
20Nanofilm by Thermal Evaporation sampleQCMVaporization or sublimation of a heated material onto a substrate in a vacuum chamberfilmvaporAu, Cr, Al, Ag, Cu, SiO, othersPressure must be held lowto prevent contamination!vacuum~10-7 torrsourceThere are many otherthin film manufacturingtechniquesresistive, e-beam, rf or laserheat sourcevacuumpump
21Nanofilm by Electroplating VcathodeanodeCuSO4 dissolved in waterWorkingElectrode(WE)Counter(CE)Cu(0) –> Cu2+ + 2e-"oxidation"If using an inert Pt electrode:2 H2O –>O2 + 4H+ + 4e-"reduction"Cu2+ + 2e- –> Cu(0)
22Imaging Nanostructures Atomic Force Microscope (AFM)
23"Optical Lever" for Profilometry laser.cantilever
24"Optical Lever" for Profilometry Long light path and a short cantilever gives large amplificationlaser.cantilever
25Atomic Force Microscope AFM Cantilever ChipAFM Instrument HeadAtomic Force MicroscopeLaser Beam PathCantilever Deflection
37NANOFABRICATION BY SELF ASSEMBLY Diblock CopolymersBlock “B”Block “A”PSPMMA~10 nmScale set by molecular sizeOrdered Phases10% A30% A50% A70% A90% A
38Versatile, self-assembling, nanoscale lithographic system CORE CONCEPTFOR NANOFABRICATIONDepositionTemplateEtchingMaskNanoporousMembrane(physical orelectrochemical)Remove polymerblock within cylinders(expose and develop)Versatile, self-assembling, nanoscale lithographic system
44Magnetic Data Storage ? N S ‘0’ N S S N S N ‘1’ Current Magnet with unknown magnetic stateNSSNSCurrentN‘1’
45Binary Representation of Data only 2 choicesone bit“1” or “0”two bits00, 01, 10, 114 choicesthree bits000, 001, 010, 011,100, 101, 110, 1118 choicesn bits has 2n choicesFor example, 5 bits has 25 = 32 choices...more than enough to represent all the letters of the alphabet
46Binary representation of lower case letters 5-bit "Super Scientist" code:ex: k = 010111SNOR(Coding Activity: Use attractive and repulsive forces to "read" the magnetic data!)
47Improving Magnetic Data Storage Technology The UMass Amherst Center for Hierarchical Manufacturing is working to improve this technologyGranular MediaPerpendicularWrite HeadSoft Magnetic UnderLayer (SUL)coil1 bitY. Sonobe, et al., JMMM (2006)• CHM Goal: Make "perfect" mediausing self-assembled nano-templates• Also, making new designs for storage
48Electrodeposited Nanowires in a Nanoporous Polymer Template (Mask) nanowires in a diblockcopolymer templatenanoporous templatePulse reverse electrodeposition results in improved microcrystalline structure and improved magnetic properties (larger perpendicula magnetocrystalline anisotropy)1x1012 wires/in2
49Solar Cells Benefit: Sun is an unlimited source of electronic energy. Konarka
50Electric Solar Cells Sunlight - + + - Made from single-crystal silicon wafers (conventionally)Sunlightwires-cross-sectional view“load”n-type siliconVoltagep-type silicon++-CurrentThe load can be a lamp, an electric motor, a CD player, a toaster, etc
51Nanostructured Solar Cells Sunlight-“load”Voltage+CurrentMore interface area - More power!
52Nanotechnology R&D is interdisciplinary and impacts many applications PhysicsChemistryBiologyMaterials SciencePolymer ScienceElectrical EngineeringChemical EngineeringMechanical EngineeringMedicineAnd othersElectronicsMaterialsHealth/BiotechChemicalEnvironmentalEnergyAerospaceAutomotiveSecurityForest productsAnd others
53My Advice to Students: Pursue your interests Ask questions Be clever Re: Your futureMy Advice to Students:Pursue your interestsAsk questionsBe cleverDo!Thanks for visiting UMass and learning about nanotechnology!
54Thanks from the UMass team! Thanks learning about nanotechnology!