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Interdisciplinary approach:
• Paper science,• Graphical science,• Physics, • Chemistry,• Biology,• Electronics,• Management,• …
New designs,New materials,Nanomaterials?
Printed antennas, sensors
Printed displays,indicators
Intelligent packaging
Includes: Internal and external sensing Monitoring of parameters vital for the goods inside Parameter recording and storing for later analysis (optimization) Shelf life calculation Communication Protection (anti‐tampering, anti‐counterfitting, damaged…) Transport and storage monitoring Life cycle monitoring
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Intelligent packaging
TRENDI RAZVOJA
Bar code >>>> RFID
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QR code + mobile phone extra info web shopping, marketing …
Intelligent packaging
PRINTED ELECTRONICS Flexible materials (paper, carton, foil…) Functional printing inks Conventional printing (not same perspective) Passive electronic components (antennas, sensors …) Active electronic components (displays, ICs …)
Intelligent packaging
prevod
na TB
Printed electronics– functional inksConventional print (illusion)
– (CMYK) …
PRINTED ELECTRONICS
Intelligent packaging
PRINTED HUMIDITY SENSORS Capacitive humidity sensors Gas sensor modification (functional coating) RFID sensor platform
Intelligent packaging
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FABRICATED WITH SCREEN PRINTING• Commercial conductive ink (polymer with
silver micro/nano‐particles)• Heat curing• Simple to fabricate• Low resolution• Surface roughness• Issue with electrical contacts
TWO SENSOR TYPES• Lateral (comb) type capacitor ‐ A• Flat plate capacitor – B
SENSOR DIMENSIONS• 1X1 CM (A,B)• 2X2 CM (A,B)• 3X3 CM (A,B)• ARRAYS WITH ALL DIMENSIONS
OF BASE TYPE SENSORS.
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1x1 cm
2x2 cm
3x3 cm
3x3 cm array
2x2 array 1x1 array
Flat plate
1x1 cm 2x2 cm
Layout of the printing form
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MAIN GOALS:• Design and fabricate capacitive humidity
sensors of different geometry andconfiguration.
• Test sensors on different cellulose based substrates.
• Find the optimum design (electrically and economically) for future work.
The ultimate goal is to fabricate a RFID enabled system with screen printed sensors for use in smart packaging applications.
Substrates and sensor labelingVimax (recycled paper) C1 (1×1 cm), C2 (2×2 cm), C3 (3×3 cm); comb typeM‐Liner (cardboard) K1 (1×1 cm), K2 (2×2 cm), K3 (3×3 cm); comb typePackPro (food packaging paper) V2 (2×2 cm); comb typePoly‐carbonate foil PC (2×2 cm); comb type
ASSUMPTION:SENSOR RESPONSE IS A FUNCTION OF SUBSTRATE.
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Testing in the humidity chamber at the Faculty of electrical engineering, Ljubljana
CONSTANT TEMPERATURE: T = 23°CRELATIVE HUMIDITY RANGE: 35 % ‐ 80 % Rh
MEASURING QUANTITIES:• CAPACITANCE [F]• CONDUCTANCE [S]4 MEASUREMENT SERIES:
From low (35 % Rh) to high (80 % Rh) – 5 % Rh step, step duration 1hFrom high to low – 5 % Rh step, step duration 1hCycling the Rh from 35 % ‐ 80 % ‐ 40 % Rh – 10 % Rh step, 1hCycling the Rh from 80 % ‐ 35 % ‐ 70 % Rh – 10 % Rh step, 1h• Can track up to 16 sensors simultaneously with arbitrary period ( 30s ).
0
0.5
1
1.5
2
2.5
3
x 10-10
Cap
acita
nce
[F]
Time response
11:17 12:34 13:35 14:39 15:42 16:44 17:45 18:52 20:01 21:10 22:20
35
40
45
50
55
60
65
70
75
80
Time
Rh
[%]
C1C2C3K1K2K3PCV2RhSetRh
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Time response plotDATA FROM CYCLING MEASUREMENT (35 % ‐ 80 % ‐ 40 % RH)• Lazy and lower response at low Rh (< 50 % Rh)• Saturation and over response at Rh > 80 %
30 35 40 45 50 55 60 65 70 75 800
0.5
1
1.5
2
2.5
3
3.5x 10
-10
Rh [%]
Cap
acita
nce
[F]
Capacitance vs Rh
C1C2C3K1K2K3PC2V2
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C vs Rh plotDATA FROM CYCLING MEASUREMENT (35 % ‐ 80 % ‐ 40 % RH)• Logarithmic response type• Hysteresis (evident at Rh > ~60 % Rh) higher capacitance with
moist sensor (from 80 % to 40 % Rh) lower capacitance with dry sensor (from 35 % to 80 % Rh)
40 45 50 55 60 65 70 75 800
10
20
30
40
50
60
Rh [%]
SR [%
]
Relative sensitivity (SR)
C1dryC1moist
C2dry
C2moistC3dry
C3moist
K1dryK1moist
K2dry
K2moist
K3dryK3moist
PC2dry
PC2moistV2dry
V2moist
P2dryP2moist
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Relative sensitivity plot: SR vs RhDATA FROM CYCLING MEASUREMENT (35 % ‐ 80 % ‐ 40 % RH)• All sensors in the same region of sensitivity (also P‐C foil)• More sensitive when moist
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In conclusion:• SENSOR RESPONSE IS NOT A FUNCTION OF SUBSTRATE, IT'S
A FUNCTION OF CONDUCTIVE INK (POLYMER).• LOGARITHMIC RESPONSE.• HYSTERESIS.• REPEATABILITY IS POOR.• CAN BE USED FOR SIMPLE APPLICATIONS WHERE IT'S ONLY
IMPORTANT TO DISTINGUISH BETWEEN DRY AND WET.• CHEAP (MASS PRODUCIBLE), EASILY FABRICATED AND
INTEGRATED INTO PRODUCTS (EG. PACKAGING).
PROBLEMS• ENERGY SUPPLY• ELECTRICAL CONTACTS
META‐PAPER / FREQUENCY SELECTIVE SCREEN
• The frequency selective surfaces (FSS) are periodic structures in either one or two dimensions which perform a filter operation. Depending on their construction, material and geometry, they are divided into low‐pass, high‐pass, band‐pass and band‐stop filters.
173D 2D - printed
META‐PAPER / FREQUENCY SELECTIVE SCREEN
APPLICATIONS• Frequency splitting• Cassegrain reflectors• Frequency filtering (reflecting)• EM radiation protection• Wireless data protection• Antenna power directing• IR radiation reflecting• …
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META‐PAPER / FREQUENCY SELECTIVE SCREEN
STRUCTURE (2D – PRINTED)• Periodic conducting patterns (meta‐cells)• Dimensions proportional to wave‐length• Passive antenna (reflector) analysis approach
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META‐PAPER / FREQUENCY SELECTIVE SCREEN
MEASUREMENT RESULTS• Screen‐printing Ag‐ink• Operation @ 3,0 GHz
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META‐PAPER / FREQUENCY SELECTIVE SCREEN
• IR reflector (~10 micron print?)• Printed antennas (radar, Wi‐Fi; performance?)• Cheap solutions (maritime, cars…)
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