Nanotechnology. EE 211 Introduction to Nanotechnology, Winter 2006 Lecture 1

Nanotechnology EE 211 Introduction to Nanotechnology, Winter 2006 Lecture 1 The big question What is Nanotechnology ? It depends who you are tal...
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Nanotechnology

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

The big question

What is Nanotechnology ?

It depends who you are talking to.

“What I do is nanotechnology.”

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Our definition of Nanoscience • any ‘useful’ object whose functionality depends on at least one dimension being on the sub-micron scale • functionality is determined or improved by use of nanoscale

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Nano-products

Live more. Care less. NANO-CARE® fabric protection imparts a revolutionary, carefree quality to wrinkle resistant fabric that minimizes stains, offers superior liquid repellency and maintains wrinkle resistance. NANO-CARE® enhanced fabrics cause water and oil spills to bead up and roll off fabric without penetrating the fibers. NANO-CARE® enhanced fabrics add value to your favorite products when you are looking for the next level in easy care, wrinkle resistant fabrics. Because the performance is "built-in" on a nano or submicron scale, these features are inherent to the nature of the fabric. This "built-in" quality means permanent performance for the life of the garment, all while maintaining breathability. NANO-CARE® fabric protection enhances market-driving, wrinkle resistant fabrics with the added value of stain repellency. Your customers will look good… and so will you. KEY FEATURES •Superior Stain, Water, And Oil Repellency •Resists Wrinkles •Breathable Fabric •Preserves Original Hand •Easy Care •Durable Performance

nano tennis balls (Wilson double core)

Alter/improve product performance using nano-structures EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Qdots.com

(Seydel, Science, 300, 80, (2003))

Replace organic dyes for biomedical imaging with nano-structures EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Qdots.com Principal Scientist Mosaic Gene Expression System Development Job Requirements: Ph.D. or M.D. with industrial experience (total experience of 5+ years may include some academic or postdoc experience). B.S./M.S. with more extensive experience (>8/>6 years) and a proven track record of scientific achievement. Experience with developing assays in the Life Sciences or Diagnostic industry and launch of a commercial product is a requirement. Strong background in molecular biology and mathematic analyses required. Micro array and /or RT-PCR experience is desirable. Experience with statistical analyses considered a plus.

Manufacturing Technician, Mosaic Gene Expression Analysis System Job Requirements: BS in the life sciences, physical sciences, or engineering with 0-2 years or relevant work experience or an AA with 4 years of relevant work experience. Manufacturing or screening experience with robotic equipment is highly desirable. Knowledge of, or experience with, gene expression analysis is considered beneficial. Must have excellent verbal and oral communication skills. This position will require accurate record keeping and adherence to standard operating procedures and batch records. The ability to contribute to process improvements and changes is highly desirable Manufacturing Scientist Job Requirements: Advanced degree in organic or protein chemistry, biochemistry; and 010 years experience process development or in a research or manufacturing environment; knowledge of protein conjugation, analytical and purification techniques is highly desirable.

• established industries ‘go nano’ (e.g. electronics) • novel applications, companies and industries emerge (e.g. nanotubes) • often interdisciplinary EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

What’s going on on the nanoscale?

(courtesy R. Ram, MIT)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Scientific interest in the nanoscale

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Potential Government expenditures for nanotechnology: • $270 Mio in 2000, $495 Mio in 2001, $961 Mio in 2004, $3.7B in 2005-08 • covers all government agencies (NSF, NIH, NASA, DoE, DoD) • centers for nanotechnology (national and state level) • small business initiatives (SBIR), $70M in 2003

Foresight Institute: www.foresight .org • educate public about nanotechnology • ensure the beneficial implementation of nanotechnology.

Foresight Challenges: • Meeting global energy needs with clean solutions • Providing Abundant Clean Water Globally • Increasing Health and Longevity of Human Life • Maximizing Productivity of Agriculture • Making Powerful Information Technology Available Everywhere • Enabling the Development of Space EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Feynman’s lecture “There is plenty of room at the bottom.” (R. Feynman 1960) “Can we write the Encyclopedia Brittanica on the head of a pin?” Encyclopedia Brittanica: 80,000 pages, area: 7.5 million sq.in. pinhead: 1/16 in. diameter Required size reduction: 25,000 (diameter) Reduced dot size: 8nm diameter (contains 1000 atoms) Current status of “nano-writing” technology: E-beam lithography: resolution 10nm Placement of atoms on surface: single atom

(NSF) EE 211 Introduction to Nanotechnology, Winter 2006

Yes, we can do it! Lecture 1

Fabrication and Imaging “How do we write it?” “How do we read it?” Fabrication methods: • Top-down: Lithography, pattern transfer, “sculpting” Problems: Definition of feature size, alignment • Bottom-up: Self assembly Problems: controlled arrangement, regularity

Imaging methods: • Optical Problems: wavelength of light on micron scale • Electron-optics: Problems: Expensive, complicated • Scanning probe methods Problems: slow due to scanning

(Veeco) (Veeco)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Scaling

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Why Scaling? Behavior of things changes on the small scale. Possible reasons: • geometry • graininess • novel effects and regimes

characteristic dimension d

d Consider dependence of various quantities on dimension d

How strong is a nano-sized lever? How effective is a DC motor at the nanoscale? …

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Scaling laws Geometry volume V: mass, weight, buoyant forces, …

V ∝ d3

versus surface S: pressure, convection, …

S ∝ d2

S 1 ∝ V d • surface-to-volume ratio increases as dimensions shrink • Surface effects matter (often neglected in analyses) • ”nanoparticles are only surface” • look for applications where scaling is advantageous EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Scaling laws Example: Nano soccer ball

23cm

10nm

• keep total volume the same • calculate total surface area • 1.5x107 nano-balls • S/V ratio 1.15x107 times higher !!! EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Scaling laws • S/V ratio scales with number of balls N for fixed volume as

1 S S0 = ⋅N 3 V V0

• same total reaction volume does not imply same reaction • specifically: surface-dependent (catalyzed) reactions

catalytic converter carbon nanotube array EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

MEMS and NEMS

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Definition MEMS = Micro-Electro-Mechanical System • component sizes between 1µm and 1mm • achieves engineering function(s) by electromechanical means • core elements: sensor/actuator and signal transducer

e.g. pressure sensor accelerometer

e.g. motor, mirror

(after Hsu)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Requirements Requirements for MEMS: • material for µm size structures • fabrication for µm size features (micromachining) • interaction mechanism (scaling) • affordable

MEMS materials: • single crystal Si, glass • quartz, Ge, SiC, GaAs • SOI: silicon on insulator

• GaP, InP

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

MEMS fabrication Bulk micromachining • features are sculpted in bulk of substrate • often wet etching • dependence on substrate crystallography (after Madou)

Surface micromachining • layered structure on top of substrate • sacrifical layers • combination of dry/wet etching (after Madou)

• independent of substrate crystallography

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Surface micromachining Example: ARROW waveguide fabrication (UCSC/BYU collaboration)

Silicon Dioxide Silicon Nitride Silicon

1 SiO 2

SiN SiO2

2

metal

SiO 2 Silicon

Silicon

3

SiO2 SiN

4

air

Silicon

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Applications Car industry

(after Madou)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Applications Integrated PCR

(after Burns)

• thermal cycling for PCR, small thermal mass • surface chemistry relevant suitable for nanoparticles • can design emission wavelength with size

fluorescence from CdSe/ZnS quantum dots

(Bawendi et al)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Optical processes Application: Fluorescence labeling in biology • fluorescent molecule = fluorophore • selectively tag cell parts with fluorophore • locate and identify

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Optical processes Chemically synthesized nanoparticles (dots) • based on group II (Zn,Cd) and group VI (S,Se,Te) elements • synthesized from solution • core-shell (ZnSe/ZnS) or organic cap layer • spherical, relatively narrow size distribution • size tunable emission wavelength

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Optical processes Application: Replacement for molecular dyes

• dots have narrower emission spectrum • larger signal • higher selectivity

dots mark tumor location

(Seydel, Science, 300, 80, (2003))

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Applications II: Magnetism

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Magnetic storage 2. Nanomagnets in magnetic storage

Read-Write Head: Writer: electromagnet tiny, fast, and high field

Reader: field sensor

400 Gbyte

tiny, fast, and electric

4 Gbyte

Deskstar 7K400

70 kbits/s 2 kbits/in2 50 x 24” disks $10,000/Mbyte EE 211 Introduction to Nanotechnology, Winter 2006

757 Mbits/s 61.7 Gbits/in2 5 x 3.5” disks $0.0006/Mbyte

Microdrive (2003) 50 Gbits/in2 1 x 1” dia disk

Lecture 1

Magnetic storage Writing

a

GMR Read Inductive Write Element Sensor

disk movement

d D = 8 nm

W t

S S

N

B

N N

S S

N N

SS

Recording Medium

key parameters: t = 15 nm, B = 35 nm, W = 190 nm, d = 9 nm

EE 211 Introduction to Nanotechnology, Winter 2006

N N

S 10 nm

Grain size distribution = 8.5 ± 2.5 nm Grain boundaries = 1 – 1.5 nm Lecture 1

Single-domain nanomagnets Patterned media: digital magnetic storage • only two orientations allowed • digital memory possible

M

M 6-nm FePt Particles

`0`

100 nm

`1`

MFM

SEM • nanofabrication allows for high density EE 211 Introduction to Nanotechnology, Winter 2006

100 Gbit/in2 bit cell ~130 particles 4:1

13 Tbit/in2 1 Tbit/in2 bit cell bit cell ~13 particles ~1 particle 1:1 1:1 Lecture 1

Nano-magneto-optics Nano-magneto-optics

P

E E

P Φ(M)

M 100 nm

M

courtesy T. Savas (MIT)

• magnetization-dependent polarization rotation • optical pulses for time-resolution EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Nano-magneto-optics • cavity-enhanced MOKE rotation

NSOM fiber tip

Signal-to-noise

Ein Er0

Er1

• anti-reflection coating next to magnets

Er2

Signal-to-noise Dielectric coating

n

L

• near-field collection with etched fiber tip

AR coating n

M

dspot

Signal-to-noise n

substrate

Φ ≈ Φ on

1+

Roff

1 Aspot − Amag

Ron

Amag

EE 211 Introduction to Nanotechnology, Winter 2006

Spatial (lateral) resolution

Lecture 1

Nano-magneto-optics Kerr rotation angle [deg]

1

(a) 1µm

b)

(b) 250nm

SiN

SiN +NSOM

0.1 (c) 100nm

(d) 75nm

(i)

0.01 5µm

(e)

Bare Ni (ii)

0.001 0.01

0.1

1

magnet diameter [µm] N. Qureshi et al. Nano Lett. 5, 1413 (2005)

10

Φ ≈ Φ on

1+

Roff

1 Aspot − Amag

Ron

Amag

• far and near field observation of individual single-domain nanomagnets • near-field signal constant for reduced dimensions EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Nanomagnets in biology and medicine Drug delivery • target drugs to specific site using magnetic field • results in lower dosage • particles are injected, moved into tissue with magnetic field

e.g. FeRx Inc. MTC = magnetically targeted carrier

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Applications III: Biology

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Basic biology concepts Nucleic acids • two forms: DNA = deoxyribonucleic acid, RNA = ribonucleic acid • three building blocks: ring compound, sugar, phosphate

DNA, RNA

DNA, RNA

DNA

DNA, RNA

RNA

(after Bao)

• sequence of nucleotides determines genetic behavior • double (ds) and single (ss) stranded; ds: T A, G C (after Prasad)

• 3D helix structure through hydrogen bonds

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Cellular processes 2.1 Cell biosynthesis (Central ‘dogma’ of biology) • proteins need to be synthesized

gene expression Reverse translation ???

• transcription: copy DNA onto mRNA • translation: protein synthesis according to code • ribosomes: ~20nm diameter; consist of RNA-protein complexes • no 1:1 correspondence between RNA and amino acid sequence • parts of DNA are not translated • reverse translation currently impossible

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Basic biology concepts Example: Translation process in ribosomes

70S ribosome ribosomal protein

ribosomal protein

30S subunit

50S subunit

(rRNA)

(rRNA)

peptide chain

tRNA (A) tRNA (P) tRNA (E) • ribosome: molecular machine • transfer nucleotide sequence of mRNA into protein sequence • numerous molecular movements in ribosome during protein synthesis

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Challenges in biology Applications for nanoscale pharmaceuticals and medicine

http://greenpeace.org.uk/MultimediaFiles/Live/FullReport/5886.pdf EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Bio-NEMS (Nature Biotech, 19, 856)

• disease detection requires protein recognition • PSA (prostate cancer protein) binds selectively to cantilever • free energy change causes deflection • sensitive at clinically relevant levels

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Electrical single DNA molecule analysis

C

(Akeson, Deamer, UCSC)

• sense and distinguish individual DNA molecules • use biological nanopores (α-hemolysin in lipid membrane) • electronic detection of passage of individual DNA molecules

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale α-hemolysin nanopore

dsDNA

ssDNA

13 Å

22 Å

• passes single-stranded DNA, blocks double-stranded DNA • limited lifetime (hours)

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale

loop

stem

6bp

6bpA14

TT

TT

T T GC CG AT AT GC CG

T T GC CG A T AA GC CG

5′ ∆G° :

3′

-8.2 kcal/mol

5′

6bp

6bpA14

1 second

10 ms

100% 52% 10%

3′

-4.3 kcal/mol

• free energy sensitive to single base-pair mismatches • mismatch appears in blockade duration

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Synthetic nanopore • nanopore alternative: Focused Ion Beam etching in silicon nitride

(Li, Harvard)

1 .8 n m

a

b

• variable size • nano-fabricated

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Molecular beacons

primer

hybrid

molecular beacon

(after Tyagi)

• MB = hairpin DNA + fluorophores at end • fluorescence quenched in hairpin state • fluorescence when hybridized to matching sequence • hybridization detection • single nucleotide mismatch sensitivity EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Integrated single molecule optics

Life happens in non-solid environments: liquids and gases!!!

Integration

? microscopy with single-molecule sensitivity

microfluidics

• no planar integrated optics for liquids and gases on chip • huge potential for fully integrated devices • affects many fields, especially life sciences: medicine, biology, chemistry, molecular biology, toxicology … EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale Vision: light, compact biosensors with single molecule sensitivity

Liquid core waveguide

• planar platform • fiber-optic coupling • single molecule control • single molecule sensitivity

• compact • light • fast • inexpensive

Will impact both basic science and diagnostic applications EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale ARROW: AntiResonant Reflecting Optical Waveguides

Hollow core

Mode image at output facet (see left)

• first hollow-core ARROW • Si-based fabrication • other substrates possible • µm cross sections, cm lengths • picoliter volumes • light guiding (D. Yin et al., Opt. Express 12, 2710 (2004) D. Yin et al., Appl. Phys. Lett. 85, 3477 (2004)) EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale

signal

excitation Liquid-core ARROW

y

z

x

Photon counts

Solid-core ARROW

3.6 10

4

3.5 10

4

3.4 10

4

3.3 10

4

3.2 10

4

3.1 10

4

20µm

SEM image of intersecting solid and hollow-core ARROW waveguides

• intersecting waveguide arrays

-1

0 1 2 3 4 5 Approximate number of molecules

6

Detected fluorescence vs. # of molecules In excitation volume

• excitation volume ~100 fl • fluorescence detection with fully planar beam geometry • single molecule sensitivity EE 211 Introduction to Nanotechnology, Winter 2006

(H. Schmidt et al., JSTQE 11, 519 (2005) D. Yin et al., submitted) Lecture 1

Biology on the nanoscale PMMA reservoir

Pump waveguide

Liquid-core waveguide

• liquid core connected to reservoirs • 10µl fluidic reservoirs • demonstrated integrated platform EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale V

300 250 200 I [nA]

150 100 50 0 -5 0 -2 0

0

20

40 V

DC

60 [V ]

80

100

120

0 .1

1 0 .8

0 .0 5 0 .6 0 .4

V=0

∆t = 12 s v=0.3mm/s

0

Voltage(V)

Fluorescence(V)

V=200V

0 .2 -0 .0 5 0

Integrated device on measurement stage: Pt wires for electrical signal, fiber for fluorescence

-0 .2 400

405

410 415 T im e [s ]

-0 .1 420

Top: current vs. voltage Bottom: Electrical (blue) and optical (red) signals detected

• demonstrated electrophoretically controlled fluorescence EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

Biology on the nanoscale integrated DBR filters

Integration of filter

detector

Integration of detector

Multiple cells on chip (multiple analytes, single pump) source

Integration of source

• Integration with larger microfluidic system • Integration with microelectronics •… EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1

EE 211 Introduction to Nanotechnology, Winter 2006

Lecture 1