microcontact printing copyright © 2012 board of trustees, university of illinois. all rights...
TRANSCRIPT
Microcontact Printing
Copyright © 2012 Board of Trustees, University of Illinois. All rights reserved.
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Objective
You will:
• become familiar with techniques used in nanotechnology.
• design and make a stamp for patterning a silver surface.
• pattern a silver surface by stamping a single layer of molecules onto it.
• test the properties of the patterned silver surface.
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Motivation
• Printing large area electronic devices--such as wide-screen televisions.
• Printing these electronic devices on flexible materials like plastic.
• Microcontact printing can pattern large area electronic devices on flexible materials at a low cost.
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Nanotechnology Applications
Biosensors
Flexible Electronics
Printed Circuits
Electronic Paper
Definition
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Micro contact printing:
is a prefix that means one millionth.says that two objects are touching.takes place when a material like ink is transferred by the contact.
transfers ink in a very small pattern from a rubber stamp onto another surface.
Microcontact printing:
1 m 1 mm 1 µm
Microcontact Printing Process
master
moldPDMS
polymerize, release
stamp
inker pad
ink solution
release
etch
silver substrate
SAM
ink
Making a Stamp
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Transparency Mold
Molded PDMS
Master Image
Patterning a Silver Surface
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Thin Silver SurfaceProtective “Ink” Layer
Molded PDMS Stamp
Protective “Ink” Layer
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1-hexadecanethiol
PDMS Stamp
Sulfur (thiol)
Hexadecane
Silver Surface
Silver Etchant Protected Regions
Soft Lithography
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Silicon Wafer Silicon WaferSpin Coat Photoresist
Spin Coat Photoresist
Transparency Master
Transparency Master
Ultraviolet LightUltraviolet Light
Developer: Remove unexposedphotoresist
Developer: Remove unexposedphotoresist
Cure PDMS
Etch Silicon
Inker Pad Silicon Wafer (or other substrate)
InkStamp
EtchFinished Product
Finished Product
Soft Lithography
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Silicon Wafer
Silicon Wafer (or other substrate)
InkStamp
Spin Coat Photoresist
Transparency Master
Etch
Ultraviolet Light
Finished Product
Developer: Remove unexposedphotoresist
Etch Silicon
Finished Product
Microcontact Printing Press
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Today’s Activity
1. Ink Stamp2. Stamp silver3. Etch silver4. Observe pattern5. Silver glass