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Volt in Amper
Električni tok je definiran kot količina naboja, ki v danem časovnem intervalu preteče skozi dani presek.
Električna napetost nam pove, koliko dela je potrebno opraviti za premik neke elektrine po neki poti v električnem polju.
Enota za napetost je Volt [V]
Enota za tok je Amper [A]
Volt vs Amper = OhmRazmerje med napetostjo in tokom določa električna upornost.
R = U / I [Ω]
Volt * Amper = Watt(Moč)
P = U * I [W]
Električni tok s pretakanjem skozi snov proizvaja toplotni učinek oz. segreva tvarino, skozi katero se pretaka. Prav tako lahko ustvarja tudi magnetni, kemični ali mehanski učinek – ta učinek bo toliko močnejši, kolikor je večji zmnožek jakosti toka in napetosti, ki je ta tok pognal skozi tokokrog. Ta zmnožek se zato imenuje moč ali električni učinek toka. Veličino moči označujemo s P, enote moči pa se izražajo v vatih (krajšava W). Vat se mestoma imenuje tudi voltamper (VA), čeprav naziva glede na pomen nista povsem istovetna.
Moč 1 W proizvaja tok moči 1 A tedaj, ko je ustvarjena s pomočjo napetosti 1 V – oz. porabnik, ki je skozenj pod napetostjo 1 V pretekel tok jakosti 1 A, troši 1 W moči.
Elementi v elektroniki
Analogni:• Upor• Kondenzator• Tuljava• Dioda• Tranzistor• …
Digitalni:• Logična vezja• Mikroprocesorji• (Mikro)računalniki• …0 in 1(RFID, Internet, „pamet“)
Upor
U/I karakteristika je linearna
Mehanska analogija: Trenje, zračni upor…
Kondenzator (kapacitivnost)Kondenzator je elektrotehniški element,ki lahko shranjuje energijo v oblikielektričnega polja.
Količino shranjene energije imenujemokapacitivnost, kjer so enote Faradi.
Mehanska analogija: vzmet
Tuljava (induktivnost)Dušilka, navitje ali tuljava je elektronski element z dvema priključkoma, katerega glavna značilnost je induktivnost.
Induktivnost
Mehanska analogija: masa
TransformatorTransformator je statična električna naprava, ki preoblikuje (transformira) električno energijo ene izmenične napetosti in enega izmeničnega toka v električno energijo druge izmenične napetosti in drugega izmeničnega toka iste frekvence. Je najenostavnejši električni stroj.
PolprevodnikiPolprevodnik je monokristalna snov, ki ima brez dovedene energije lastnosti električnega izolatorja, pri dovolj veliki dovedeni energiji pa ima lastnosti slabega električnega prevodnika. Od tod tudi njegovo ime. Uporabljajo se za izdelavo nelinearnih elektronskih elementov (dioda, tranzistor, čip, triak,...). Sodobne elektronike si ne moremo zamišljati brez polprevodnikov. Najbolj znan polprevodnik v elektroniki je silicij, uporablja pa se tudi germanij.
Dioda
TranzistorTranzistor je polprevodniški elektronski element s tremi priključki, ki ga uporabljamo za ojačevanje, preklapljanje, uravnavanje napetosti, modulacijo signalov in v številne druge namene. Je eden ključnih gradnikov sodobne elektronike in uporabljen v praktično vsaki elektronski napravi.
Električno vezjeElektrično vezje je sestavljeno iz najmanj enega vira električne energije, enega porabnika in vodnikov, ki povezujejo porabnik in vir.
Sestavin v električnem krogu je lahko več oblik, ki lahko vključujejo elemente, kot so upori, kondenzatorji,stikala, transformatorji in elektronike. Elektronska vezja vsebujejo aktivne sestavine, običajno polprevodnike in po navadi kažejo nelinearno obnašanje, ki zahteva kompleksne analize. Najenostavnejši električni sestavni deli so tisti, ki se označijo kot pasivni in linearni.
Izdelava vezja
Tiskanina
Tiskanina
Polaganje elementov
Avtomatizirana izdelava PCBjev
Integrirana vezja (čipi)
What is?q Intelligent packagingqMeta-paper / Frequency Selective Screen
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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:q Internal and external sensing q Monitoring of parameters vital for the goods insideq Parameter recording and storing for later analysis (optimization)q Shelf life calculationq Communicationq Protection (anti-tampering, anti-counterfitting, damaged…)q Transport and storage monitoringq 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
prev
odna
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
30
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)
C1dry
C1moist
C2dry
C2moist
C3dry
C3moist
K1dry
K1moist
K2dry
K2moist
K3dry
K3moist
PC2dry
PC2moist
V2dry
V2moist
P2dry
P2moist
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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.
363D 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• …
37
META-PAPER / FREQUENCY SELECTIVE SCREEN
STRUCTURE (2D – PRINTED)• Periodic conducting patterns (meta-cells)• Dimensions proportional to wave-length• Passive antenna (reflector) analysis approach
38
META-PAPER / FREQUENCY SELECTIVE SCREEN
META-CELL
39
META-PAPER / FREQUENCY SELECTIVE SCREEN
MEASUREMENT RESULTS• Screen-printing Ag-ink• Operation @ 3,0 GHz
40
META-PAPER / FREQUENCY SELECTIVE SCREEN
41
META-PAPER / FREQUENCY SELECTIVE SCREEN
• IR reflector (~10 micron print?)• Printed antennas (radar, Wi-Fi; performance?)• Cheap solutions (maritime, cars…)
42
ALL ACHIEVABLE BY PRINT!
• Intelligent packaging / electronic components• Meta-paper (fundamental physical property of
paper altered)
43
ACKNOWLEDGEMENT:Thanks to Vipap d.d., for supporting and fully financing the meta-paper research.
Elektroluminiscentni zasloni
44
Elektroluminiscentni zasloni
45
Kapacitivna stikala
46
47
48
Prihodnost
49
• Novi materiali• Tiskani tranzistorji (polprevodniki)• Tiskana integrirana vezja• Tiskani računalniki (paralelni)• MEMs