NSF Nanoscale Science and Engineering Center for High-rate Nanomanufacturing (CHN)

Ming Wei(UML), Liang Fang(UML), Arun Kumar(UML), Jia Shen(UML), Jason Chiota(UML), John Shearer (UML), Jun Lee(UML), Sivasubramanian

Somu(NEU), Xugang Xiong(NEU), Carol Barry(UML), Ahmed Busnaina(NEU), and Joey Mead (UML)

Directed Assembly of Polymer

Structures for High-rate

Nanomanufacturing

NEU: Directed assembly,

MEMS, fabrication,

nanoscale contamination

control

UML: High volume polymer processing

and assembly

Semiconductor & MEMs fab

7,000 ft2 class 10 and 100

cleanrooms

6 inch completer wafer fab,

nanolithography capabilities

UNH: Synthesis, self-assembly

Fully-equipped synthetic labs 10,000 ft2 +

Plastics processing labs 20,000 ft2 + Compounding and forming equipment

A unique partnership

Team Strength and Capability

Director: Ahmed Busnaina, NEU

Deputy Director: Joey Mead, UML, Associate Directors: Carol Barry, UML; Nick McGruer, NEU; Glen Miller, UNH;

Jacqueline Isaacs, NEU,

Group Leader: David Tomanek, MSU

• State of the Art:

• Pure self-assembly produces regular patterns

• Nanomanufacturing

Through High-

rate/High-volume

Templates for

Guided Self-

Assembly of

Nanoelements

• Will provide the

tools to fabricate a

wide array of

products

How Does Directed Assembly and

Transfer Work?

Carbon

nanotube

directed

assembly

Nanowire Template Directed Assembly Using Electric Fields or Chemical Functionalization

No Alignment

Nanoparticle

directed

assembly

Directed

assembly

of polymer

High-rate

< 1 min

Nanotrench Template Directed Assembly Using

Electrophoresis or Chemical Functionalization

Nanoparticle

directed

assembly

down to 10 nm

Selective

directed

assembly of

polymers

Carbon

nanotube

directed

assembly

down to 80

nm lines

High-rate

< 1 min

App Phys

Lett 2006,

Pat. Pend.

Adv Mater,

2009,

Pat Pend.

App Phys

Lett 2007,

Small 2007

Pat. Pend.

Directed Self-Assembly of Polymers

(Nano-)Template:

Resulting concentration:

Kazmer, UML

Flexible Electronics

Conducting polymer

Biosensors (radiation, cancer,

anthrax, etc.)

+ IgG

Templates

Chemical Force Electrostatic Force

Nanotrench

TemplateDPN

TemplateNanowire

Template

Template Directed Assembly

Part 1 Part 2

Part I: Directed Assembly of

Polymer Blends and Single

Polymers by Chemical Forces

State of the Art

Direct Assembly of Block Copolymer

Nature 424, 411-414 (2003), Science 308, 1442-1446 (2005)

PS-b-PMMA

PS-b-PMMA/PS/PMMA

Blend

Nealey et al.:

• Long range order nanopatterns

with sub-100 nm dimensions by

assembly of block copolymers

• Does not permit the preparation

of non-uniform structures using

block copolymers alone

• Homopolymers added to obtain

non-uniform patterns

State of the Art

Direct Assembly of Polymer Blends

Ginger et al.:Dot Nanopatterns down to150 nm

by self-assembled monolayers

(SAMs) via dip pen nanolithography

(DPN)

JACS, 127, 4564-4565 (2005)

Budkowski et al.:2 µm line patterns by self-

assembled monolayers (SAMs)

via micro-contact printing

Macromolecules, 38, 8486-8493 (2005)

Nonumiform structures and Rate Effects

Si substrateAu PMMA

MUAMMUAM

Au

MUAMPMMA

PS

PAA

Spin PMMA Patterned PMMA by E-beam Assembly of MUAM

Patterned

MUAM/ODT

Patterned

PS/PAA

ODT

Patterned

MUAM

Directed Assembly of Polymer Blends by

Nanotrench Templates

1 m

Homogeneous Assembly of PS or PAA

Nanotrench

PS on ODT areas MUAM areaPAA on MUAM areas ODT area

HS CH3HS+

NH3 Cl-

MUAM: ODT:

PAA and MUAM PS and ODT

1 m

Directed Assembly of PS/PAA

1 m1 m

Heterogeneous Assembly of Blend - PS and PAA

PS/PAA blend (70/30)

PS assembled on nonpolar areas (light)

PAA assembled on the polar regions (dark)

Process conditions are critical

for good assembly

30 seconds

No annealing

Spinning Speed

3000 rpm

5000 rpm

9000 rpm

400 nm 300 nm 200 nm 100 nm 50 nm

Pattern Line Width of Template

Effect of Spin-coating Speed

Non-uniform Patterns by Heterogeneous Directed

Assembly of PS/PAA Blends

Enabled by

polymer blends

– Spin coating

– 30 seconds

– No annealing

Circle arrays

90˚ bends T-junctions

Square arrays

• Chemically functionalized

templates successfully used to

assemble polymer blends on

MHA/ODT surface.

• Achieved assembly of PS/PMMA

polymer blends on non-uniform

geometries.

• Polymer domains were patterned

from 300 nm to 50nm on the same

template.

Directed Assembly of Polystyrene/Polymethyl methacrylate Blends Using Nano-scale Alkanethiol Patterned SurfacesUniversity of Massachusetts Lowell

Jason Chiota, John Shearer, Ming Wei, Carol Barry, and Joey Mead

PMMA on

MHA

(Light)

PS on ODT

(Dark Spots)

PS/PMMA (50/50 ratio) assembled onto

MHA/ODT with pattern sizes from 300 to 50 nm

Magnified results of

PS/PMMA in 300, 250,

200 nm.

Magnified results

of PS/PMMA in

150 and 100 nm.

Magnified results

of PS/PMMA in 50

nm.

Multi-scale Patterned Polymer Blends

DPN Templates

Template design

Part II: Directed Assembly of

Conducting Polymer onto Nanowire

Templates and Pattern Transfer

onto Flexible Substrates

Direct Assembly of Conducting

Polymers by Electric Field

* : Li, G. et al, J. AM. Chem., Soc., 2005, 127, 4903

Li et al, reported a thin film of

Polyaniline (PANi) on electrodes, but

did not reproduce the electropattern.*

Little has been reported about direct

assembly of conducting polymer by

using electric fields.

Assembly of Conducting Polymers using

Nanowire Templates

PANi

Gold

150 nm width, 160 nm height, and

100 m length

Pattern

Dimension:

Gold Line width 100 nm

Pitch 500 nmDC, 2 V 1 min AC, 2V, 100 Hz, 1 min

140 nm width, 50 nm height, and

100 m length

Assembly of Conducting Polymers at Different Times

Dielectrophoresis

1 min

30 s

15 s

100 Hz, 2 V

Electrophoretic Assembly and Transfer

Polymer transfer

with heat and pressure

-

+

Template is Reused

Assembled polymer

40 µm40 µm

Transfer to polyurethane

Template after transfer

Precise directed electrophoretic assembly ofconductive polymer - polyaniline (PANI)

Requires 10 volts for < 1 minute

Template design critical for assembly into patterns

Transfer of polymer wires onto substrates

Dependent on polarity of transfer substrate

Wei et al., J. of Macromolecular Rapid Comm., 27, 2006

Scale up of Transfer Process

PANi and CNT Structures

• Transfer of conducting polymer and CNTs

• Transfer time 10 s, total cycle time 40 s

Thermoforming machine and mold picture

Thermoforming mold sketch

Pattern transferred at 179º

C in 15 s at 30mm HgCNTs deposited on patterned

structure at 20 V in 15s

Infra – red

bandsPU sheet Heated

sheet

Plug pressure

Vacuum

pressuremold

Transferred patterned

PANi

30 sec 20 sec

Transfer using Thermoforming Process

Transfer from rigid template to compliant substrate

Summary - Accomplishments

• Developed high rate assembly and transfer (<1 min)

• Nanotrench templates and DPN template– Direct assembly of polymer blends

– Pattern size down to 100 nm

– 30 seconds, no annealing required (Nanotrench)

– Non-uniform geometry and multi-scale in one step fashion

• Nanowire templates – Directed assembly of conducting polymers

– Pattern size down to 140 nm

– 15 seconds

• Transfer – Complete transfer to flexible substrate by thermoforming

– Cycle time 50 seconds

Acknowledgements

The authors wish to acknowledge the support of the National Science Foundation under grant number NSF-0425826

The authors also acknowledge the Kostas Nanomanufacturing Center at NEU