Molecular

Printing: A

Chemist’s

Approach to a

“Desktop Fab”

Molecular

Printing: A

Chemist’s

Approach to a

“Desktop Fab”

Chad A. Mirkin

Northwestern University

Department of Chemistry and

International Institute for

Nanotechnology

Modern Printing Tools Revolutionized

the World

It is exceedingly difficult to print with molecules and many materials

on the “nanometer scale”

Information transfer, the semiconductor industry, the microelectronics

revolution, and gene chips

Desk Top Printer

Is It Possible to

Create A “Desk

Top Fab”?

Dip Pen Nanolithography (DPN)

Attributes of DPN: • Direct-write

• High resolution: 10 nm line width, ~5 nm spatial resolution

• Positive printing

• Writing and imaging with same tool

• Molecule general

• Substrate general

• Serial or massively parallel

The NSCRIPTORTM

An Integrated DPN System

Destructive

Delivery of

Energy

Constructive

Delivery of

Materials

Nanografting

Nanoshaving

Anodic Oxidation

“Millipede”

DPN

Scanning Probe Lithography: A

Dichotomy is Emerging

Sol Gel Materials

4mm

290 nm

Dip-Pen

Nanolithograpy

Hard Materials

Nanoparticle Arrays Silicon Nanostructures

12 nm

Nanogap Electrodes

1 mm

500 nm

~45 nm

90 nm

85 nm

100 nm

135 nm

185 nm

Silver Nanostructures

Gold Nanostructures

Single-Walled Carbon

Nanotubes

Virus Nanoarrays

Ultrahigh Density DNA Arrays

Combinatorial DPN Templates

Bio-nanoelectrics

Protein Nanoarrays

Small Organic Molecules

100 nm

4mm

Protein Nanostructures

Conducting Polymers Soft Materials

550 nm 550 nm

4 µm

Polymer resists

The Ultimate in High Density Arrays

Biological Nanoarrays:

• More than just miniaturization with higher density

• New opportunities for biodetection and studying biorecognition

• Templates for guiding the assembly of larger building blocks

• Open up the opportunity to study multivalency and surface cooperativity

Robotic Spotter

(1 Dot/200x200 mm2)

High Resolution DPN

(100,000,000 Dot/200x200

mm2)

Feedback Controlled Lithography

(100,000,000,000 Dot/200x200 mm2)

Conventional Microarray

Low Resolution DPN

(50,000 Dot/200x200 mm2)

Can DPN be Used To Generate Multicomponent

Templates that are Used to Recognize and Larger

Biological structures and Organisms?

Protein (Human IgG)

Virus (HIV)

8.5 nm 120 nm

Living Cells

Spores (Anthrax)

~20 µm ~15 µm

Single Virus Nanoarrays

DPN-Generated Biological Nanoarrays

Multicomponent DNA

Nanoarrays Phospholipid Arrays

Multicomponent Protein

Nanoarrays

Cell Arrays on Nanopatterned Substrates

• Sub 50 nm many mm resolution

• Large Array Patterning

• Multi-component Patterning Capabilities

• Reconstructing the extracellular matrix at the nm scale

5 mm 4 mm

4 mm

80 mm

DPN Generated Positive Photomasks

DPN

ODT

Au Etch

Cr Etch Au Etch

Quartz

Cr Au

Cr Photomask

-1.0 -0.5 0.0 0.5 1.0

-0.8

-0.4

0.0

0.4

0.8

Empty electrode

PPY nanotube

PPY nanotube with UV

Curr

ent (n

A)

Voltage (V)

Device Characterization Replicated Au Electrode

Jang et al, Small, 2009, 5, 1850

DPN Spot Size Is Independent of

Applied Force

Molecular diffusion from point source is independent of applied

force between tip and surface.

1.5 mm

20×90 µm

NanoPrint Array II: 55,000 tips ~ 1 cm2

Pen fabrication yield >99% (preliminary)

In collaboration

with J. Fragala, NanoInk

100 mm

5 µm

400 nm

100 nm

40×40 dots at 400 nm pitch

~88 million features in ~20 min

Polymer Pen

Lithography

(2008)

Hard-Tip, Soft

Spring Lithography

(2011)

Beam Pen

Lithography

(2010)

Cantilever-Free Cantilever-Based

DPN

(1999)

2D 55,000 Pen

Cantilever Array

(2006)

1D Multipen

Cantilever Array

(2000)

Key Advance 1:

Deposition of

materials

rather than

energy

Key Advance 2:

Use an elastomeric

pyramid on a solid

backing for cantilever-

free printing

Key Advance 3:

Move the “spring”

from the tip to a

polymer backing

layer Thermal DPN

(2004)

Giam, et al. Angew. Chem. 2011, 50, 7482.

Scanning Probe Block

Copolymer Lithography

(2010)

Development of Cantilever-Free

Scanning Probe Lithography

PDMS Pen Array Fabrication

Huo, F et al. Science. 2008, 321, 1658.

11 Million Pen Polymer Array

(A)11 million pen array. (B) SEM image of the polymer pen array. (C) An etched gold pattern on a

4 inch Si wafer. (D) Optical microscope image of gold patterns.

A B

D C

Huo, F et al. Science. 2008, 321, 1658.

High Resolution

High Throughput

Mask-free Nanofabrication

Huo, F et al. Science. 2008, 321, 1658.

Polymer Pen Lithography (PPL)

100 circuits in

1 cm2 with 500

nm and 100

µm features

100 μm

500 nm

Printing Circuit Designs on Multiple Scales

100 µm

500 nm 500 nm

Huo, F et al. Science. 2008, 321, 1658.

Time Dependence

Feature Edge Length vs Dwell Time

Huo, F. et al. Science. 2008, 321, 1658.

Liao. et al. Small, 2010, 6, 1082.

Z-Piezo Dependence

Feature Size vs Z-Piezo Extension

Feature Size Control

Force Dependent Pattern Feature Edge Length vs Force

feature top

top

L L FNEL

Tip-Height Sensing: Force Dependence

bottom top

ZF NEL L

H

F1 < F2

Liao. et al. Small, 2010, 6, 1082.

Tilted PPL Array Z Height of the Tilted Pen Array

0( , , , ) sin( ) sin( ) x y x yZ N N Z DN DNθ: tilting angle to the y axis

φ: tilting angle to the x axis

M1, M2 and M3:

Motors holding the pen array θ = 0.07°

φ = 0.06 °

Liao. et al. Nano Lett. 2010, 10, 1335.

Leveling the Pen Array by Force

Experimental Ftotal vs θ and φ

• At the perfect leveling position, the total force

reaches its global maximum

• For each fixed θ, the force reaches its local

maximum when φ=0 and vice verse

• Around the perfect leveling position, the

gradient is very large

( , , , ) ( , , , ) bottom top

x y x y

EL LF N N Z N N

H

( , ) ( , , , ) x y

total x y

N N

F F N N

φ/ ° θ/ °

F total /

mN

F

tota

l / m

N

Calculated Ftotal vs θ and φ

Leveling the Pen Array by Force

Liao. et al. Nano Lett. 2010, 10, 1335.

θ = 0°

2.54 ± 0.05 mm

θ = –0.01°

4.68 ± 0.89 mm

θ = +0.01°

5.33 ± 1.03 mm

0o

–0.01o

+0.01o

Leveled Patterns

Liao. et al. Nano Lett. 2010, 10, 1335.

Multiplexed Protein Patterning by PPL

Inkjet print multiple

protein into inkwells

inkwells

Inkwells with different

fluorescent proteins

Pattern multiplexed

protein arrays

Multiplexed patterning

of protein arrays

Zheng, Z et al. Angew Chem. 2009, 48, 7626 .

Feature size control

Combinatorial Libraries Generated by

Tilting PPL Array

Printed Area

PPL array

substrate

High contact force

Low contact force

Feature width = 1.34 μm

Feature pitch = 2 μm

Feature width = 475 nm

Feature pitch = 2 μm

Large area patterns

Why PPL?

• Patterns over large areas for studying thousands to millions of cells

• Ability to produce combinatorial arrays with different feature sizes (micro to nanoscale)

• Ability to level the PPL array and produce homogeneous features over large areas

100 μm

CBFα1 actin DAPI

MSC Differentiation Studied by PPL-

Generated Combinatorial Arrays

Massively Parallel Hybrid Silicon

Pen Nanolithography

10 μm

1 mm

Ultra-High Resolution

High Throughput

Mask-free Nanofabrication

Easy Alignment

Z-piezo Glue

Soft backing layer

Si tip

100 μm

500 μm

Pen Tip Array

1 um

22 nm

Different light reflection

In contact with the surface

Before contact with the surface

Massively Parallel Hybrid Silicon

Pen Writing

Time Dependence

Feature Edge Length vs Dwell Time

Z-Piezo Dependence

Feature Size vs Z-Piezo Extension

Feature Size Control

5 μm

Z=12 μm

10 μm

8 μm

4 μm

6 μm

0 1 2 3 40

200

400

600

800

1000

1200

Do

t d

iam

ete

r (n

m)

Contact time (s1/2

)

4 6 8 10 120

200

400

600

800

1000

1200

Dia

me

ter

(nm

)

Z-piezo Extension (um)

5 μm

i ii

iii iv

i

ii

iii

iv

10 μm

Feature Size Resolution

Average Feature

Size = 42 nm

5 μm

5 μm 5 μm

Block Copolymer Assisted TBN

-10

10

30

50

0 2 4 6 8 10

100 nm

100 nm 90 °

5 µm

Distance (µm)

Heig

ht

(nm

)

5 µm

2 µm

Block Copolymer (BCP) Patterns

BCP Deposition (Height) BCP Deposition (Phase)

AFM Height Profile

Cai et al, submitted

Single Nanoparticles Formed by

Block Copolymer TBN

• The spatial resolution is controlled by the piezo-controlled tip position

• Fourier transform analysis confirms uniformity of the AuNP pattern

• Sub-10 nm single crystal Au NPs are formed by the BCP method

• TEM and Diffraction patterns confirm single crystal composition of the

nanostructures

TEM and Diffraction of AuNP SEM of AuNP Array

Cai et al, submitted

Nanoparticle Size Control

Cai et al, submitted

1 µm

Large-Scale Patterning

Au NPs on SiO2

Cai et al, submitted

Particle Size Consistency

Au NPs on SiO2

Cai et al, submitted

Growth Trajectories: Cryo-TEM Movie of

Ripening Process

2 nm

FOR OFFICIAL USE ONLY – Not Cleared for Open Release

Formation of Single

Nanoparticles Observed

-120 degrees C, ~ 1 min frame interval

FOR OFFICIAL USE ONLY – Not Cleared for Open Release

Two Mechanisms are Occurring

-120 degrees C, ~ 5 min frame interval

• Coalescence observed for particles closer than ~ 5 nm

• Ostwald ripening observed for particles further apart

Fabricating a Beam Pen Array

BPL array 200 nm Aperture 1 μm Aperture 2 μm Aperture

100 μm 2 μm 2 μm 20 μm

Beam Pen Lithography (BPL)

Huo et al, submitted

BPL Scheme Au dot arrays by BPL 10 x 10 dot array

Chicago Skyline Arbitrary patterns by BPL

Develop

Evaporation +

liftoff

Patterning

150 μm

100 μm

20 μm

Beam Pen Lithography (BPL)

Huo et al, submitted

Mask-Assisted BPL

• Drawbacks:

– Photo mask is needed

– Can not in-situ address the pens

Mask assisted BPL Patterns of “NU” with selected pens

Huo et al, submitted

Development of Molecular Printing Tools Parallel Printing

Serial Writing

Woodblock Printing (China ~200)

Printing Press (Gutenberg, 1439)

Movable Type (Bi Sheng, ~1041-1048)

μ-Contact Printing (Whitesides, 1993)

Quill Pen (~2000 BC)

Dip-Pen

Nanolithography (DPN) (Mirkin, 1999)

Ball-Point (Loud, 1888)

Polymer Pen

Lithography (PPL) (2008)

Beam Pen

Lithography (BPL) (2010)

Hard Tip, Soft Spring

Lithography (2010)

Scanning Probe Block

Copolymer Lithography (2010)

A Step Towards “Desktop Nanofabrication”:

Take Home Messages

• DPN and PPL are workhorse molecular printing research

tools, which allow researchers to rapidly prototype and

study molecule-based structures.

• The barrier to scanning probe parallelization is

crumbling; PPL, BPL, and SPBCL open the door for low

cost and rapid nanofabrication procedures.

• The techniques are poised to make the transition from

primarily research tools to high throughput synthesis

and fabrication tools, especially in the life sciences.

World Use of Dip Pen Nanolithography

Australia: Swinburne U. – Nicolau Canada: U.of Alberta – Buriak China: Chinese Acad. of Sci .(Lanzhou) – Li CIST – Hua Peking U. – J. Liu , Y Li. Chinese Acad. of Sci. (Shanghai )- Zhang Chinese Acad. of Sci.(Beijing) –Z. Liu Xi’an Jiaotong U. – Zhang, Liu Southwest U. – Tang Columbia: Servico Nacional de Aprendizaje (SENA) France: CNRS France – Joachim Germany: Inst. für NanoTechnologie, Forschungszentrum Karlsruhe– Fuchs Ludwig Inst.– Bein Max Planck Inst. – Bastiaen Great Britain: U. of Cambridge –Rayment Imperial College – Cass U. of Ulster U. of Strathclyde –Graham Hong Kong: Xu

India: CEERI – Kumar Jawaharlal Nehru Cen. for Adv. Sci. Research– Rao Indian Inst. Sci. – Brar Israel: Hebrew U. – Willner Italy: Politec. di Milano – Levi U. degli Studi di Milano Bicocca – Sassella

Japan: NAIST– Ushijima Nagoya U.– Ichimiya Korea: Samsung Electronics, Co. Seoul Nat. U. – Nam, S. Hong Pusan Nati. U. – Il Kim Sungkyunkwan U. – HJ Kim Korea U. –Ahn Yonsei U.–H. Jung Netherlands: U. of Twente– Reinhoudt, Velders Singapore: Nanyang Tech–Liu , Huo, Zhang , Boey, Huang Spain: Inst. Català– Maspoch, Garcia, Martinez Parc Cientific–Samitier Taiwan: Acad. Sinica–Tao Nat. Chiao Tung U.– Sheu Nat. Taiwan U.– Lin Schmidt Scientific

United States: Air Force Research – Naik, Stone Albany NanoTech – Kossow Brookhaven – Ocko Cal.Tech.– Collier Cal. State – Schwartz Corning Inc Science & Tech Duke U. – J. Lui, Chilkoti George Mason U. – Espina Georgia NanoFab – Lewis Harvard U. – Lieber Lawrence Berkeley – De Yoreo Loyola U. – Holz

MIT – Stellacci NASA Langley – Watkins Naval Research – Byers, Whitman, Sheehan N. Carolina State U. – Narayan Northwestern U.– Dravid, Liu, Mirkin, Wolinsky, Espinosa NYU – Braunschweig Ohio State U.– Lee Penn State U.– Weiss Portland State University- Yan, La Rosa Purdue U. – Ivanesivic Rensselaer Poly.– Nalamasu Sandia NL – Hsu Stanford U. – Bao Stevens IT – Libera Texas A & M – Banerjee, Batteas Texas Tech – Vaughn, Weeks Tufts U. – Kaplan

UMass Lowell - Mead UC Davis – G. Liu UCSB – Hu U. of Chicago – Mrkisch U. of Florida – Ren UIUC – C. Liu, U. of Maryland – Gomez U. of N. Carolina – Zauscher U. of Washington – Ginger Washington Tech Center – Allen

Mirkin Group

Acknowledgements

Funding

AFOSR, ARO DARPA (TBN Program),

HSARPA, NSF, ONR, NIH,

DOD NSSEF Fellowship

Collaborators Prof. Chang Liu (NU)

Prof. Harald Fuchs (Münster, Germany)

Dr. Steven Lenhert (Münster, Germany)

Prof. Mark Ratner (NU), Prof. Michael Bedzyk (NU)

Prof. Vinayak Dravid (NU), Dr. Morley Stone (WP AFRL)

Prof. Milan Mrksich (University of Chicago)

Prof. George Schatz (NU), Dr. Rajesh Naik (WP AFRL)

Prof. Hua Zhang (Nanyang Technical University, Singapore)

Joe Fragala (NanoInk)