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Microsystems LaboratoryUC-Berkeley, ME Dept.
1Liwei Lin, University of California at Berkeley
Introduction to Nanotechnology and Nanoscience – Class#2
Liwei Lin
Professor, Dept. of Mechanical Engineering Co-Director, Berkeley Sensor and Actuator CenterThe University of California, Berkeley, CA94720
e-mail: [email protected]://www.me.berkeley.edu/~lwlin
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Microsystems LaboratoryUC-Berkeley, ME Dept.
2Liwei Lin, University of California at Berkeley
Course Homepage - 3
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Microsystems LaboratoryUC-Berkeley, ME Dept.
3Liwei Lin, University of California at Berkeley
Outline
� Nanoscale Properties� Nanofabrication: Top-down Technologies
& Bottom-up Processes� (some materials from Professor Lydia Sohn)
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Microsystems LaboratoryUC-Berkeley, ME Dept.
4Liwei Lin, University of California at Berkeley
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Microsystems LaboratoryUC-Berkeley, ME Dept.
5Liwei Lin, University of California at Berkeley
DNA Detection
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Microsystems LaboratoryUC-Berkeley, ME Dept.
6Liwei Lin, University of California at Berkeley
DNA Detection
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Microsystems LaboratoryUC-Berkeley, ME Dept.
7Liwei Lin, University of California at Berkeley
Molecular ElectronicsThe Future?
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Microsystems LaboratoryUC-Berkeley, ME Dept.
8Liwei Lin, University of California at Berkeley
National Nanotechnology Initiative
Even though nanoscience & nanotechnology had existed for many years, it was Present Bill Clinton in January 2000 who catapulted (for better or for worse) the field into mainstream science & engineering and society—Proposed the NNI which has now become a multibillion dollar investment in the US—see http://www.nano.gov for history and current info. on the NNI
• Estimated world-wide investment on nanotechnology and nanoscience is $8.6B in 2004
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Microsystems LaboratoryUC-Berkeley, ME Dept.
9Liwei Lin, University of California at Berkeley
Nanotechnology Explosion
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Microsystems LaboratoryUC-Berkeley, ME Dept.
10Liwei Lin, University of California at Berkeley
Some big numbers
Federal 2002 nanofunding $622 millionEstimated nanosales volume in 2015 $1.2 trillionStates with active nanodevelopments 24
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Why should I take this course?
11Liwei Lin, University of California at Berkeley
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Who is in this class (2015)?
12Liwei Lin, University of California at Berkeley
25
7
2
2
2
1
1
1
1
0 5 10 15 20 25 30
Mechanical Engineering
Materials Science
Chemical Engineering
Chemistry
Bioengineering
Engineering Physics
Chemical Biology
Molecular/Cell Biology
Civil Engineering
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Microsystems LaboratoryUC-Berkeley, ME Dept.
13Liwei Lin, University of California at Berkeley
4
29
5
2
0 5 10 15 20 25 30 35
Graduate
Senior
Junior
Sophomore
Who is in this class (2015)?
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Microsystems LaboratoryUC-Berkeley, ME Dept.
“Nanoscience & ME”
What does a mechanical engineer do in nanoscience?
Materials scientist?Chemical engineer?
Chemist, bioengineer, biologist, physicist, civil engineer?
14Liwei Lin, University of California at Berkeley
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Research� Nanoscience is hot!� National labs, academia, industrial research
organizations (IBM, PARC)
15Liwei Lin, University of California at Berkeley
http://www.mrs.org/science-as-art/
“Nano-Explosions”Color-enhanced scanning electron micrograph of an overflowed electrodeposited magnetic nanowire array (CoFeB), where the template has been subsequently completely etched. It’s a reminder that nanoscale research can have unpredicted consequences at a high level.
- Fanny Beron, École Polytechnique de Montréal, Montréal, Canada
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Microsystems LaboratoryUC-Berkeley, ME Dept.
16Liwei Lin, University of California at Berkeley
MEL. LinL. SohnX. ZhangC. Grigoropoulos
MSEJ. WuO. DubonR. Ramesh
ChemER. MaboudianA. KatzS. Muller
ChemistryP. YangP. AlivisatosG. Somorjai
Civil EngineeringS. GovindjeeW. NazaroffC. Ostertag
BioengineeringD. LiepmannK. HealyL. Lee
PhysicsA. ZettlM. CrommieF. Hellman
Berkeley Nanotechnology & Nanoscience Institute (BNNI)Marvell Nanofabrication Laboratory, SDHBerkeley Sensor & Actuator Center (Cory Hall)Berkeley Nanotechnology Club https://www.ocf.berkeley.edu/~atwu/
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Microsystems LaboratoryUC-Berkeley, ME Dept.
17Liwei Lin, University of California at Berkeley
NanoScience in Mechanical Engineering
Energy – energy storage, renewable energySensing – gas sensors, chemical sensors, etc.Optics
Cu2O nanowires for photo-electrochemical water splitting (Lin Lab)
“Superlens”(Zhang Lab)
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Microsystems LaboratoryUC-Berkeley, ME Dept.
18Liwei Lin, University of California at Berkeley
NanoScience in Materials Science
� Nanomaterial synthesis, material properties, and characterization
In-situ TEM nanomechanics (Andrew Minor Lab)
Strain engineering of VO2nanobeams (Junqiao Wu Lab)
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Microsystems LaboratoryUC-Berkeley, ME Dept.
19Liwei Lin, University of California at Berkeley
NanoScience in Bioengineering
� Virus-based piezoelectric energy generation� Super-resolution imaging� Drug delivery
Seung-Wuk Lee Lab:
M13 bacteriophage piezoelectric generator6 nA, 400 mVOperates a liquid crystal display
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Microsystems LaboratoryUC-Berkeley, ME Dept.
20Liwei Lin, University of California at Berkeley
NanoScience in Physics & Chemistry
� Physics• Nanomechanics• quantum computation• quantum teleportation• artificial atoms
� Chemistry• carbon nanotubes• Nanowires• self-assembly• structures based on DNA• supermolecular chemistry
Lateral Quantum Dot Leo Kouwenhoven
Superconducting QuBitJohn Clarke
Carbon Nanotube Cees Dekker
Tetrapod Paul Alivisatos
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Microsystems LaboratoryUC-Berkeley, ME Dept.
21Liwei Lin, University of California at Berkeley
NanoScience in Civil Engineering
Materials – nano-reinforced materialsEnvironmental chemistry Water treatment
Nanomaterials for water purification:Journal of Nanoparticle Research (2005)7: 331–342
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Microsystems LaboratoryUC-Berkeley, ME Dept.Nanotech in the Bay Area
22Liwei Lin, University of California at Berkeley
Nanomix - hydrogen storage
Neophotonics – photonic integrated circuitsNanogram Devices-nanomaterials synthesis
Sila Nanotechnology – Li-ion batteries
Alphabet Energy– Thermoelectrics Quantum Dot Corp. – Nanocrystals for biomolecular detection
HP – quantum science researchAgilent-chemical/medical diagnostic equipmentNanosolar – low cost PV
Crossbar Inc – non-volatile memory
Nanostellar– emission control & energy efficiency
http://www.nanotech-now.com/business-by-location.htm
Optiva– LEDs
IBM – Li-air batteries
Lumiphore–biological detection
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Microsystems LaboratoryUC-Berkeley, ME Dept.
23Liwei Lin, University of California at Berkeley
Take ME118ME 218N!
“Nano PacMan”
Scanning electron microscope image of a copper oxide cluster, 3.5 microns in diameter, prepared by evaporation and condensation over an alumina substrate. The smiley nose and eye are present in the original SEM image, which has only been color-enhanced. - Elisabetta Comini, University of Brescia, Italy
http://www.mrs.org/s10-science-as-art-winners/
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Microsystems LaboratoryUC-Berkeley, ME Dept.
24Liwei Lin, University of California at Berkeley
Why Nanostructures?
IC & MEMS > 100 nm• Batch manufacturing – low cost• Multi-domain Integration (Electrical, mechanical,
fluidic, optical …) Nanotechnology < 100 nm
• Quantum effects in nanostructures (quantum dots, wires, tubes …)
• High surface area to volume ratio – high sensitivity
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Microsystems LaboratoryUC-Berkeley, ME Dept.
25Liwei Lin, University of California at Berkeley
Size-Dependent Properties
At the nanometer scale, properties become size dependent!
For example,
•Thermal properties •Mechanical properties•Optical properties•Electrical properties •Magnetic properties
New properties enable new applications
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Microsystems LaboratoryUC-Berkeley, ME Dept.Surface Area to Volume Ratio
26Liwei Lin, University of California at Berkeley
(a) (b)
(c) (d)
Tomato seed
Au nanoparticle
Cell
http://web2.clarkson.edu/programs/goia_group/res_materials_modif_au.php
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Chemical reactivity
27Liwei Lin, University of California at Berkeley
vs
Au nanoparticle
InertCatalyst
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Microsystems LaboratoryUC-Berkeley, ME Dept.
28Liwei Lin, University of California at Berkeley
Mechanical Properties� At the nanoscale, surface and interface forces become dominant.� For example,
Adhesion forcesCapillary forcesStrain forces
Surface coatings are extremely important to prevent stickingin nanoscale electro-mechanical systems (NEMS)
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Microsystems LaboratoryUC-Berkeley, ME Dept.
29Liwei Lin, University of California at Berkeley
Stiction in Micro/Nano Structures
� Strong capillary forces during the releasing process and pin down the free-standing microstructure
Anchor Micro Beam Structure
Silicon Substrate
Stiction AreaLiquid
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Microsystems LaboratoryUC-Berkeley, ME Dept.
30Liwei Lin, University of California at Berkeley
Microstructure Stiction Examples� Shorter beams may survive stiction problems*
*Carlos Mastrangelo, Univ. of Michigan
Mastrangelo et al., “Mechanical Stability and Adhesion of MicrostructuresUnder Capillary Forces,” IEEE/ASME J. of Microelectromechanical Systems,Vol. 2, 44-55, 1993
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Microsystems LaboratoryUC-Berkeley, ME Dept.
31Liwei Lin, University of California at Berkeley
Anti-Stiction Coating
� Self-assembled monolayer (SAM) coating by using OTS (octadecyltrichlorosilane) - C18H37SiCl3
hydrophilic0 - 30o
Silicon Substrate
concave
~ 114o
hydrophobicSilicon Substrate
convex
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Microsystems LaboratoryUC-Berkeley, ME Dept.
32Liwei Lin, University of California at Berkeley
Melting Temperature
Nanocrystal size decreases
Surface energy increases
Melting point decreases
3 nm CdSe nanocrystal melts at 700 K compared to Bulk CdSe at 1678K
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Quantum Mechanics
33Liwei Lin, University of California at Berkeley
vs
5 g/cm3
E ≈ kT
Quantum dot
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Microsystems LaboratoryUC-Berkeley, ME Dept.
34Liwei Lin, University of California at Berkeley
Rayleigh Light-Scatteringof Nanocrystals
Shape, Size, and Composition Matter
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Microsystems LaboratoryUC-Berkeley, ME Dept.
35Liwei Lin, University of California at Berkeley
Optical Absorption
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Microsystems LaboratoryUC-Berkeley, ME Dept.
36Liwei Lin, University of California at Berkeley
Effects of Confinement of Charge Carriers
E
D(E)
3-D 2-D
1-D
ZnO
dCdSe 4.63.63.12.42.1
d (nm)
ddCdSe 4.63.63.12.42.1
d (nm)
(Paul Alivisatos, UCB)
Example: CdSe quantum dotsFluoresces vs. wavelength
(After Arum Majumdar, UCB)
0-D
CdSe
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Microsystems LaboratoryUC-Berkeley, ME Dept.
What’s going on here?
37Liwei Lin, University of California at Berkeley
Gold nanoparticles CdSe quantum dots
vs.
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Aspect Ratio
38Liwei Lin, University of California at Berkeley
vs
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Microsystems LaboratoryUC-Berkeley, ME Dept.
39Liwei Lin, University of California at Berkeley
Electrical Properties: Tunneling Current
� At the nanometer scale, electrical insulators begin to fail to block current flow
� Quantum mechanical effect known as tunneling� Tunneling current increases exponentially as the
thickness of the insulator is decreased� Tunneling is the basis of the scanning tunneling
microscope and covalent chemical bonding
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Microsystems LaboratoryUC-Berkeley, ME Dept.
Strength-to-weight ratio
40Liwei Lin, University of California at Berkeley
45 GPa
http://www.owlnet.rice.edu/~biy/Selected%20papers/01TAPhys.pdfhttp://cnx.org/contents/f3abd155-e65d-4155-bd2c-9b435b6d2f6a@4/Carbon_Nanomaterials
vs.
520 MPa8 g/cm3
Pa/(kg/m3)1 g/cm3
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Microsystems LaboratoryUC-Berkeley, ME Dept.
41Liwei Lin, University of California at Berkeley
Nanotube Composite
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Microsystems LaboratoryUC-Berkeley, ME Dept.
42Liwei Lin, University of California at Berkeley
Size-Dependent Properties
At the nanometer scale, properties become size dependent!
For example,
•Thermal properties — melting temperature•Mechanical properties — adhesion, capillary forces•Optical properties — absorption and scattering of light•Electrical properties — tunneling current•Magnetic properties — superparamagnetic effect
New properties enable new applications