The Future of Vacuum Coated Security
Devices in the Banknote Industry
Denis Vendette
Nanotech Security Corp.
1
Overview
• Background information and definitions
• A little bit of history of vacuum coated security
devices
• Nanostructures and Plasmonics
• Conclusions
2
In the Beginning…
One of the first issued vacuum coated security device … Windowed Security
Thread
Issued by the Bank of England in 1984
Metalized windowed thread on the £20
Polyester coated with aluminum
Thread inserted during the paper making process
3
Security Devices Attributes
Authenticatable
Non reproducible
Inexpensive to manufacture
Ideal Device …
Must be easily recognizable/authenticatable by the
public
4
Why Vacuum Coating ?
Requires significant infrastructure
• Printing used to be the significant infrastructure but not anymore
with the advent of color printer and color photocopiers
Expertise and Knowhow
• specialized training and experience
Relatively simple and inexpensive when
implemented
5
Optically Variable Device (OVD)
Thin Film Optics
• Color shift foil
• OVI - Optically Variable Ink
Diffractive Optics
• Micro and nanostructures
• Coated with metal or HRI coatings
e.g. Holograms
Beyond Diffractive Optics
• Plasmonics
6
THIN FILM OPTICS
7
Color Shift
Fabry-Perot filter
Widely deployed security feature in the industry
Reflected Light
Ambient Light
Absorber Layer
Spacer Layer
Reflector Layer
Kazakhstan banknote winner of the 2015 banknote design
8
Optically Variable Ink (OVI)
Issued by Thailand 1987
Product from SICPA and Flex Products
Symmetrical Fabry-Perot
coating made into flakes
and printed
Absorber Layer
Spacer Layer
Reflector Layer
Spacer Layer
Absorber Layer
9
Optical Security Device (OSD)
High Index Layer
Low Index Layer
Black Substrate
The OSD issued by the Bank of Canada in 1989
• Issued first as an all dielectric High-Low … stack
• 1992 changed to a metal-dielectric Fabry-Perot
stack
10
Many Colors Possible
11
DIFFRACTIVE OPTICS
12
Holograms
1 um
1988 saw two banknotes issued with holograms
Austria 5000 shilling banknote
Australia commemorative 10 dollar banknote
Hologram diffractive structure in the order of 1 micron
13
Nano-Diffraction
1 um
KolourOptik™ nanohole array
compared to other OVD microstructures
Hologram Diffraction Grating
1 um
14
Nano-Optic Diffraction
Ambient
light
Green
Protective/adhesive
coating
Red
Blue
Metal
nanostructures
Bulk
Substrate
These effects can be achieved by:
• Pillars
• Holes
• Dots
15
Advantages
Micro
Nano
Rainbowing colours
Single colours
16
BEYOND DIFFRACTION:
SUBWAVELENGTH OPTICS
17
Color From Very Small Structures
100 nm
Blue Morpho Wing
100k Magnification
Combo of diffraction and
thin-film effects
NTS OVD N=nanostructres
200K Magnification
Combo of diffraction and
plasmonic
100 nm
18
Nano Structures & Plasmonic
19
Diffraction + Plasmonic Concept
Ambient light
Protective Overcoat /
Dielectric Medium
Ambient light
2D/3D nanostructures
Metal coating
Carrier Substrate (e.g.
PET)
UV or Thermal Emboss
imprint layer
Thickness: 1um to 5um
Only the colour of interest
wavelength(s) are transmitted
The same colour(s) are
seen at all viewing
angles, only in
20
transmission
White light
RGB Colors
in Reflection
White light
Dielectric medium
3D
Metal
nanostructure
Bulk Substrate
CMYK Colors in
Transmission
21
BOLD™ Bright Clearly Defined Colours
•
•
•
•
•
•
Simple
High contrast
Large viewing angle
Easy to see
Unique colors saturation
Combine with
transmission (plasmonic)
colors
22
IKON™ - RGB quality images
• Full color high definition
images
• Easy to identify in ambient
light
• High contrast
• Relatively large viewing
angles
23
Nano-Scale Pixels
– Very dense: 1 billion holes per cm2
– Use diffraction and/or plasmonic
effects
– Hard to make = hard to counterfeit
–
24
ASPECT™ 3D Color Images
• Full color stereo-images
• Bright, easy to see in
ambient light
• Relatively large viewing
angles
• Effectively a 2-frame
animation
25
KINEMA™ Animated Movies
• Mono or RGB color
animated movies
• May require use of
external light such as
phone flashlight
• Brightness can be
improved
Sampling of 48 Frame Animation
Equivalent to ~2s of cinema quality video
26
Live Action Movie
Time lapse of
KolourOptik feature during tilt
27
Plasmonic Transmission
28
Plasmonic (Only) Reflection
•
•
•
•
•
Plasmonic “printing”
Monochormatic images
RGB colour images
True colour images
Beyond print resolutions
– 1,000,000 DPI
29
Summary of Effects Achieved With
Nanostructures
1. Bold, bright contrasting
colors BOLD™
2. RGB colour images IKON™
3. 3D colour images ASPECT™
4. Animation up to 48 frames
KINEMA™
5. RGB colour images in
transmission
6. True colour reflection
30
Well Established Manuf. Platform
Origination
Recombination
Vacuum Coating
Roll-to-roll embossing / casting
Final Product
31
Vacuum coating is important
• The quality of the coatings are extremely important
– Precise thickness
– Controlling oxidation
– Coating multiple material types
– Repeatability of the process
32
Conclusions
Banknotes show no signs of disappearing
• Therefore vacuum coated security devices here to stay
Great deal of effort is applied to anti-counterfeiting
devices that are difficult to simulate
Counterfeits – compare a suspect banknote to one
you know is genuine
33
Thank You
Nanotech Security Corp.
34
Extra Slides
35
Traditional ‘Value-Added’ Features are
still possible
• Serialization
– Add a unique laser etched serial number to each
KolourOptik™ security image
• Track & Trace Solutions
– 2D Barcodes
• Tamper-Evident Features
– Micro-slits etc.
• No special materials or manufacturing processes
required … per se …
36
Colours from Structures
• Physical Phenomena
– Thin film – e.g. color shift film
– Diffraction – e.g. holograms
– Plasmonics – e.g. kolouroptik™
• Nano = higher density, smaller pixels,
more content, larger canvas
• Each phenomena need to be
differentiated, and can be combined
Fraunhofer Diffraction Intensity
37