1. Research, Design and Manufacturing of a
small scale Roll to Roll Nanoimprint
Lithography (R2RNIL) Machine
Apostolos Veltsin, University of
Glasgow, February 2016
1APOSTOLOS VELTSIN - 1106086University of Glasgow, 2016

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Nanoimprint lithography (NIL)
• Method for fabricating micro-, nano- patterns
• First devised by Prof. Stephen Chou, 1996
Roll to roll (R2R)
• Most demanding type of NIL
• High industrial scale application
• Rolls of flexible material used
• Combination on rollers
• Thermal embossing or UV curing

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Aim
• Small scale R2R printer
• Provides nano- patterned PS films
• Using UV curing
• 27 mm width
• Bottom surface of test tube array plates
• Interchangeable molds
• Maximum of 170 μm thickness
• Full customisation needed

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Approach

5. Research, development and
manufacturing
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Used printers
• Similar idea with a R2R printer
• Retrieve components
• Provided by IT service
• Recycle the rest of the components
Structural components
• MakerBeam shafts used
• Allow full customisation
• Custom brackets produced on laser cutter

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Unwinding unit
• Removable reel design
• 42 mm width
Guide
• Width of 42 mm
• Roller prevents scratches on the foil
Feeder
• Retrieved from a printer
• Two shafts with rollers, sufficient grip
• Mounted on a motor

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Corona treatment unit
• BD-20AC by Nbond
• Removable design
• Raises the surface energy of the substrate
• Improves bonding capabilities
• Electrode provides 10,000-50,000 Volts
• Causes EM interference
• Pretreating substrate fixes problem

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Coating unit
• Method chosen: slot die
• Custom made on our CNC
• Side 1: flat with 4 holes
• Side 2: 4 holes, groove cut, feed hole
• Gaskets control thickness and width
• Ideal width 30 mm
• Photocurable coating purchased

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Imprint unit
• 2 guide rollers
• 1 custom imprint shaft
• Acrylic base controls demolding angle
• PDMS mold attached with zip ties

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PDMS (Polydimethylsiloxane) mold
• Polymeric organosilicon
• Unusual rheological properties
• Flexible, good for R2R

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UV unit
• Use of 1 ultraviolet LZ4 emitter
• Wavelength of 365 nm
• Viewing angle 110°
• EYE PROTECTION NEEDED
• On an aluminium heatsink

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End feeder
• 2 shafts forced together with springs
• O-rings improve grip
• Servo runs the bottom shaft
• Bearings allow smooth movement

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Electronics - PCB fabrication
• After breadboard and Veroboard
• Fabricated in Rankine building
• Shield design
• Includes power supply that provides 12V and 5V

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Electronics box
• To fit everything together
• Safe enclosed design
• Allowing access to controls
• Firstly designed in CAD

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Front side
1. Feeder control
2. End feeder control
3. Reverse mode
4. UV led switch
Back side
5. Power supply connector
Right side
6. Servo motors switch
Left side
7. USB for microcontroller
8. UV intensity control

17. Experiments
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Surface tension
• Attension Optical Tensiometer
• Testing behavior of corona treatment
• 31 experiments took place
• Contact angles found
• Result 1: Untreated sample, 87.5°
• Result 2: Best case scenario with
corona not making interference, 58°
• Result 3: Pretreated sample at
maximum power, 9°

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Microscope results for micro- patterns
Mold Sample

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Results after 400 samples for nano- patterns

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TX spectral analysis

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Conclusion
• Successful project
• 40 runs
• 460 samples
• Speed of 3 samples/min
• 160 μm thickness
• Can be further optimised

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Further work
• Faraday cage for EM interference
• Pump for photocurable coating
• Two UV LEDs
• Improved lacquer with less UV
absorbers

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Any questions?