31 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
4How small are nanostructures? Single HairWidth = 0.1 mm= 100 micrometers= 100,000 nanometers !1 nanometer = one billionth (10-9) meter
9Example: Advancement of the iPod 10 GB200120 GB200240 GB200480 GB2006160 GB2007Hard driveMagnetic data storageUses nanotechnology!
10Magnetic Data StorageA computer hard drive stores your data magnetically“Read”HeadSignal“Write”HeadcurrentSNDiskNS1_“Bits” ofinformationdirection of disk motion
11Scaling 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!
12Why 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.)
13Nanotech: How? How to make nanostructures? How to characterize and test them?
14Making Nanostructures: Nanofabrication Top down versus bottom up methodsLithographyDepositionEtchingMachiningChemicalSelf-Assembly
18Excerpt 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....
21CHALLENGE: How thick was the film of oil? ... the Oil tho' not more than a Tea Spoonful ...... perhaps half an AcreCHALLENGE: How thick was the film of oil?Volume = (Area)(Thickness)V = A tt = V/A=2 cm320,000,000 cm2V = 1 teaspoonfulA = 0.5 acre~ 2 cm3~ 2,000 m2= cm= 1 x 10-7 cm= 1 x 10-9 m= 1 nanometer (nm)20,000,000 cm2
22An example of a FILM A monolayer NANOFILM (single layer of molecules) ~1 nm thickLangmuir filmThis is an example of SELF-ASSEMBLY
23Langmuir-Blodgett Film Must control movablebarrier to keep constantpressuremultiple dips -multiple layers
24Another film method, 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
25Nanofilm 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)
42NANOFABRICATION BY SELF ASSEMBLY Diblock CopolymersBlock “B”Block “A”PSPMMA~10 nmScale set by molecular sizeOrdered Phases10% A30% A50% A70% A90% A
43Versatile, self-assembling, nanoscale lithographic system CORE CONCEPTFOR NANOFABRICATIONDepositionTemplateEtchingMaskNanoporousMembrane(physical orelectrochemical)Remove polymerblock within cylinders(expose and develop)Versatile, self-assembling, nanoscale lithographic system
49Magnetic Data Storage ? N S ‘0’ N S S N S N ‘1’ Current Magnet with unknown magnetic stateNSSNSCurrentN‘1’
50Binary 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
51Binary 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!)
52Improving 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
53Electrodeposited 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
54Solar Cells Benefit: Sun is an unlimited source of electronic energy. Konarka
55Electric 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
56Nanostructured Solar Cells Sunlight-“load”Voltage+CurrentMore interface area - More power!
57Nanotechnology R&D is interdisciplinary and impacts many applications PhysicsChemistryBiologyMaterials SciencePolymer ScienceElectrical EngineeringChemical EngineeringMechanical EngineeringMedicineAnd othersElectronicsMaterialsHealth/BiotechChemicalEnvironmentalEnergyAerospaceAutomotiveSecurityForest productsAnd others
58Thanks for visiting UMass and learning about nanotechnology!