Pape -based
mic o luidic sensing de ices
ab ica ed by
inkje p in ing echnology
Be na Gui ao Expósi o
Mas e ’s Thesis Ad iso : Daniel Ci e io
Analy ical Chemis y labo a o y
Depa men o Applied Chemis y
Keio Uni e si y
Chemical Enginee ing Mas e ’s Thesis
Valida ed by ETSEIB (UPC)
1
Index
1. Abs ac 2
2. In oduc ion 2
2.1. Pape pa e ning echnologies 2
2.1.1. Pho oli hog aphy 3
2.1.2. Wax p in ing 3
2.1.3. Inkje p in ing echnologies 3
2.1.4. O he pape pa e ning echnologies 4
2.1.5. Pape pa e ning echnology elec ion 4
2.2. Subs a e: pape 4
2.3. Quan i a i e de ec ion o analy es 5
2.4. P e ious esea ch 5
3. Expe imen al sec ion 7
3.1. P epa a ion o he pa e ns 7
3.2. P epa a ion o he hyd ophobic ink 8
3.3. P epa a ion o he pH senso 8
3.4. P epa a ion o he pH bu e s 9
3.5. Geome y o he pa e ns 9
3.6. P in e s 9
4. Resul s and discussion 10
4.1. Simple es pa e ns 10
4.2. Two pa h pa e ns 11
4.2.1. Pa e ns C_s3w03ch15 and C_s3ci 3w03ch15 12
4.2.2. sho pa h+ pa e n se ies 12
4.3. Fou pa h pa e ns 16
4.3.1. Pa e ns 16 o 21 16
4.3.2. Pa e n C_s3s4w1ch24_c _ch04_18_ sho pa h4 17
4.3.3. Pa e n C_s45s4w1ch24_c _ch04_18_sho pa h4 18
4.3.4. Pa e n C_s45s4w1ch24_c _ch04_18_sho pa h4_sex 9 22
4.4. Simple symme y pa e ns 23
4.4.1. Pa e n Simple symme y 1 24
4.4.2. Pa e n Simple symme y 2 and Simple symme y 3 24
4.4.3. Pa e n Simple symme y 4_squa e 27
4.4.4. Pa e n Simple symme y 4 and Simple symme y 5 28
4.4.5. Pa e n Simple symme y 6 30
4.4.5.1. Tes using EPSON and Dima ix 30
4.4.5.2. Tes using only EPSON 32
5. Conclusions 33
6. Fu u e esea ch 33
7. Acknowledgemen 34
8. Bibliog aphy 34
2
1. Abs ac
The de ec ion o some analy es, o example hea y me al ions, is c ucial in loca ions such as
de eloping coun ies o humani a ian eme gencies, whe e no quali ied p o essionals o
sophis ica ed equipmen is a ailable.
In his p ojec , a de ec ion sys em using inkje p in ing echnology is de eloped. The sys em
elies on p in ing o hyd ophobic UV-cu able inks o de ine mic o luidic channels in pape , and o
p in a senso inside his channel. A e ha , a solu ion sample can be d opped in o he channel,
esul ing in a colou change o he senso . By digi ally measu ing he colou change, he analy e
quan i y can be de e mined. Ac ually, he main ocus o he p ojec is he es ing o di e en
channel geome ies in o de o imp o e hei pe o mance.
The aim o his p ojec is no only o de elop a de ec ion sys em, since nowadays a lo o hem
a e al eady a ailable. The sys em p oposed he e equi es nei he quali ied p o essionals no
e y sophis ica ed equipmen o ope a ion. Ac ually, he goal is o de ec wi h as simple
equipmen as possible. Only a compu e , a comme cially a ailable p in e and a colou scanne
would be su icien , making i possible o use hem in a eas such as de eloping coun ies o in
humani a ian eme gencies. Besides, his de ec ion sys em has been designed o be as
en i onmen ally iendly as possible.
2. In oduc ion
The sys em s udied in his p ojec , which is explained in 3. Expe imen al sec ion in mo e de ail,
consis s basically in p in ing a hyd ophobic mic o luidic channel in a piece o pape , c ea ing a
ba ie ha does no le hyd ophilic liquids o escape om he channel c ea ed. Then, he senso
eagen is p in ed inside he channel, immobilizing he senso eagen and equi ing small
quan i ies o i . Once he sys em has been c ea ed, analy e is d opped in o he channel. When
analy e sample eaches he senso eagen , colou change is de ec ed. I can be measu ed wi h
a scanne and a simple colou de ec ion p og am. F om he colou ob ained, analy e pa ame e s
such as concen a ion can be deduc ed.
The sys em p oposed is simple and low p ice. I only equi es using a p in e o p in he eagen
senso and an a ailably comme cial scanne o scan he pape and de ec he colou change.
Ac ually, a pe son wi h only basic compu e skills is able o use his sys em. In de eloping
coun ies he e is a lack o quali ied p o essionals, so i is c ucial o design an easy o use
sys em.
O he wise, indus ial ab ica ion o he sys em is cheap, since inkje p in ing echnology and UV
ligh a e a ailable echnologies in he indus y. Mo eo e , he sys em is made o pape , which is
an a ailable and cheap ma e ial, and he o he eagen s, basically he ink and senso ones, a e
expensi e, bu only small quan i ies a e used.
This sys em p esen s an inc edible amoun o applica ions. Ac ually, he e a e as much
applica ions as senso eagen s ha a e able o be p in ed in o he channels. Besides, he
sys em is cheap and easy o use, so no quali ied p o essionals o la ge amoun s o money a e
equi ed o use i , which inc eases he applica ions. Some examples o applica ions a e on si e
de ec ion o analy e p ope ies quan i ica ion in humani a ian eme gencies o in di icul access
zones (applica ions in explo a ion and mili a y ields) as well as household applica ions.
I mus be aken in o accoun ha mo e esea ch mus be conduc ed in his p ojec ield. So, in
he nea ly u u e i may subs i u e some cu en applica ions o well es ablished and commonly
used echnologies such as pho oli hog aphy.
2.1. Pape pa e ning echnologies
P in ing echnologies ha e expe ienced a g ea de elopmen du ing he las decades, and hey
a e no mo e exclusi e o he publishing sec o , since applica ions in ields like chemis y and
biology, o example, ha e been ound.
19
3
Ac ually, pape -based senso ab ica ion is one o he esea ch ields whe e p in ing
echnologies a e being applied. The idea o making senso s using pape -based echnologies is
e y a ac i e, since hey a e easy o use and may p o ide aluable in o ma ion. Howe e , a lo
o esea ch is needed o make hem cheape and mo e p ecise, since hey o en equi e so
expensi e echnologies and he in o ma ion p o ided is almos quali a i e and no as exac as
desi ed.
Mos o pape -based senso s do no equi e ex e nal equipmen o eagen s. So, his kind o
sensing de ices a e adequa ely inexpensi e o be commonly used, including in de eloping
coun ies, in eme gency i s aid si ua ions, and in home heal h-ca e se ings, in con as o
con en ional medical diagnos ic echnologies ha we e designed o ai condi ioned labo a o ies,
highly ained pe sonnel, a cons an supply o eagen s, and conside able olumes o sample.
Besides, low sample and senso olumes a e equi ed, which is impo an in he case o
a ailable clinic samples o high cos sensing eagen s.
Among he pape pa e ning echnologies a ailable, inkje p in ing, pho oli hog aphy o wax
p in ing, among o he s, may be use ul o senso ab ica ion. In his p ojec inkje p in ing
echnology was selec ed as he mos app op ia e one. Howe e , impo an ad ances a e aking
place on he o he echnologies, oo.
2.1.1. Pho oli hog aphy
In he pho oli hog aphy ield, a lo o esea ch has been conduc ed, ying o apply i o pape -
based senso s.
1
Pho oli hog aphy consis s in using a ligh o ans e a geome ic pa e n om a
pho o mask o a ligh -sensi i e chemical. One o he main p oblems i p esen s a e i s high cos ,
since sophis ica ed equipmen and quali ied p o essionals a e needed, making i mo e
expensi e o implan in mass scale p oduc ion han o he p in ing me hods, and being almos
impossible o be applied in de eloping coun ies. Besides, he subs a e used mus be
chemically ea ed, including he hyd ophilic pa , implying a subs a e con amina ion isk.
Howe e , impo an imp o emen s and esea ch a e being conduc ed o sol e hese p oblems,
ying o make i a mo e easible me hod.
2
2.1.2. Wax p in ing
Ano he p in ing echnology used egula ly is wax p in ing. Ac ually, wax p in ing is a p omising
echnology in he ab ica ion o mic o luidic pape -based analy ical de ices, since p in ing
eloci y is ex emely high and i is easible o use i o mass scale p oduc ion. Fo example, wax
p in ing akes less han 3 min o p epa e ou mul izone pla es, while pho oli hog aphic me hods
equi e abou 20 min o p epa e a single pla e.
3
Mo eo e , wax p in ing is a lexible echnology,
so i is possible o change he ab ica ion p ocess easily, like he design o he pa e ns.
The sys em consis s basically in p in ing wax on he pape and hea i in a ho pla e, pene a ing
he mol en wax in o he pape , c ea ing a hyd ophobic ba ie . I mus be aken in o accoun
mol en wax pene a ion in o subs a e makes he channels wide han in he o iginal design,
al hough some models exis o p edic channel widening.
4
O he wise, he same phenomenon
occu s in inkje p in ing echnology.
In e ms o p oducing indus ially pape based mic o luidics, wax p in ing could be a easible
echnology, due o i s eloci y, as i was old be o e, and simplici y and na u e o he p ocess
i sel . Howe e , ano he echnology should be used o p in he senso eagen , like inkje
p in ing echnology. And c ea ing a hyd ophobic ba ie could be complica ed due o wax
sol en compa ibili y p oblems.
2.1.3. Inkje p in ing echnologies
Inkje p in ing has become a use ul and easible echnology in a lo o indus ial ields o
accu a ely deposi ing e y small quan i ies ( ens o picoli e s) o ma e ials a de ined spo s on
he su ace o a wide a ie y o subs a es. Mo eo e , i is a single s ep p ocess which does no
equi e highly quali ied p o essionals o an impo an amoun o acili ies, in con as o
pho oli hog aphy. And i is a sui able echnology o scale indus y mass p oduc ion, oo. So, i s
4
ime sa ing, low cos and lexibili y will p obably es ablish inkje p in ing echnology as one o
he mos sui able p in ing echnologies in he u u e. Fu he mo e, mode n inkje p in ing de ices
ha e mul iple p in heads which a e able o p in di e en kinds o ink simul aneously, being able
o p in bo h he hyd ophobic ba ie o he pa e n and he senso eagen , and, in con as wi h
o he p in ing echnologies like plo ing, he place, ime and quan i y o liquid deposi ion can be
con olled p ecisely (“on demand” inkje p in ing echnology).
In spi e o all he ad an ages men ioned, inkje p in ing echnology has been mos ly applied in
plas ic elec onics and o he manu ac u e o polyme ligh -emi ing diodes
5-8
, and in he
analy ical chemis y ield only in he ab ica ion o elec ochemical sensing de ices.
9-10
Inkje p in ing echnology is also a easible echnology o he ab ica ion o mic o luidic sensing
de ices inco po a ing a ious chemical unc ions.
11-12
2.1.4. O he pape pa e ning echnologies
Al hough o he echnologies o pa e ning pape exis , hey a e no as impo an as he p e ious
ones. Some examples may be cu ing and plo ing.
In he case o cu ing, he kni e cos is ep esen a i e and sample and senso a e no isola ed in
a zone o he pape , ge ing we all he pape when making analysis, and consequen ly being
able o con amina e people and objec s a ound.
13
Rega ding plo ing echnology, i is no eadily adop able o he dispensing o he eagen s
equi ed o chemical sensing. Mo eo e , plo ing echnique is a con inuous line d awing me hod,
wi h he amoun o dispensed liquid being mo e di icul o con ol and, he e o e, limi ing he
esolu ion o plo ed s uc u es o 1 mm, app oxima ely. Besides, la ely el ip-based x,y-plo e s
a e being eplaced by inkje p in ing de ices, being g adually mo e di icul o ind in he ma ke
14-15
.
2.1.5. Pape pa e ning echnology elec ion
De ini ely, in o de o achie e p ope ly his p ojec goals, inkje p in ing is he mos sui able
echnology, since i is simple, cheap and lexible and i can be used in eme gency and i s aid
si ua ions. Mo eo e , i is easible o apply i in mass p oduc ion scale and mul iple p in heads
can be used o p in bo h he hyd ophobic ba ie o he pa e n and he senso eagen .
2.2. Subs a e: pape
Di e en subs a es can be used in mic o luidic sensing de ices, such as glass o pape . In he
case o his kind o sensing de ices, he subs a e mus le he analy e o low h ough i , so i
would ha e a po ous s uc u e o some ex e nal equipmen , such as ex e nal pumps, would be
used. Pape has a po ous s uc u e, since i is no mally made o cellulose ibe s. Bu pape also
has mo e ad an ages, since i is abundan , inexpensi e (6$/m
2
e en o high-quali y
ch oma og aphy pape ), sus ainable, easily and en i onmen ally iendly disposable, easy o
use, s o e, and anspo and easy o modi y chemically.
Pape is also a amilia ma e ial and e e ybody is used o i . This is an impo an ac o , since
one o he inal goals o his esea ch b anch is making sensing de ices o be used in
de eloping coun ies o eme gency si ua ions, so no quali ied p o essionals mus be able o use
hem easily. Bu pe haps i s mos impo an ad an age is ha an eno mous a ie y o inkje
p in ing echniques, conc e ely inkje p in ing echnology, is a ailable o i s unc ionaliza ion.
Mo eo e , pape has been used in he analy ical chemical ield o so many yea s, and a lo o
expe ience wo king wi h his ma e ial has been acqui ed, so a lo o ad an age can be aken
om exis ing analy ical echniques.
Pape physical p ope ies make i e y use ul o chemical analysis, oo. I is hin, ligh weigh (10
mg/cm
2
) and a ailable in a wide ange o hicknesses (0.07-1 mm). Mo eo e , i is easy o s ack,
s o e, and anspo . I s composi ion and s uc u e makes i easible o wo k wi h biological
samples, since i is made o cellulose o cellulose-polyme blends, and i can be modi ied
chemically o inco po a e a wide a ie y o unc ional g oups ha can be co alen ly bound o
p o eins, DNA, o small molecules. Ano he ad an age is he ib ous na u e o pape , which

5
p o ides o he sys em in insic capilla y pumping
18
, whence no ex e nal pumps o simila
sophis ica ed equipmen is no equi ed. Mo eo e , nowadays p in ing echniques a e able o
make sophis ica ed mic ode ices which inco po a e mo e unc ionali y, o example me al
elec odes, wi hou he need o clean ooms o o he kinds o expensi e in as uc u e.
Pape colou is whi e (i sca e s ligh ), so i p o ides con as wi h a colou ed subs a e, being
an a ailable subs a e o colo ime ic es s, and i is a ailable in a wide ange o highly
enginee ed o ms wi h a e y wide ange o p ope ies. Fo example, il e pape s wi h well-
de ined po e sizes can sepa a e suspended solids om samples be o e an assay o emo e
e y h ocy es om blood.
F om an indus ial poin o iew, pape can be easily manu ac u ed on a la ge scale by he well-
es ablished coa ing and p in ing echniques
17
, which can u he lowe he cos o he inal
p oduc s. Mo eo e , li le ini ial in es men would be equi ed.
2.3. Quan i a i e de ec ion o analy es
Quan i a i e colo ime ic de ec ion o analy es is possible by e lec ance de ec ion when he
in ensi y o he colou ha de elops in he es zones is a unc ion o he concen a ion, o
ano he pa ame e , o he analy e. In o he wo ds, he colou change p oduced in he senso
due o he con ac wi h he analy e can be de ec ed, and wi h his in o ma ion and a calib a ion
cu e, he analy e desi ed pa ame e can be calcula ed. As i was old be o e, he sys em
designed mus be easy o use, so ha no quali ied people can use i . To see he colou change
wi h he naked eye may be impossible in some cases, so simple sys ems like scanne s and
colou egis e ing so wa e may be used.
2.4. P e ious esea ch
Whi esides and cowo ke s in oduced he concep o using pa e ned pape subs a e as a
mic o luidic pla o m o mul iplex analy e de ec ion. In hei s udies, hyd ophobic polyme s we e
pho oli hog aphically pa e ned
19
o p in ed using a desk op plo e
20
on o hyd ophilic pape so
ha he millime e -sized luidic channels can be well-de ined in he pape ma ix. Owing o he
na u al capilla y ac ion o pape , luids can low along hese channels wi hou he ex e nal
pumps ha a e equi ed in he con en ional mic o luidic de ices. The use o hese pa e ned
pape pla o ms minimizes he use o sample olume and makes mul iple analysis possible.
Whi esides and cowo ke s we e able o de ec glucose and p o ein simul aneously on a single
pa e ned pape . In a mo e ecen wo k
21
, an imaging de ice (came a phone o po able
scanne ) was added o he sys em in o de o make quan i a i e analysis possible.
Ac ually, inkje p in ing can be used o deposi a wide a ie y o ma e ials, such as ino ganic
pa icles o biological species, on pape . Fo example, Pel on e al. coa ed biomolecule-
a ached mic ogel inks on pape
22
and Abe e al. p in ed an ibodies o analyze biological
pa ame e s
11
.
The concep o he sys em used in his p ojec is simila o he sys em used by Abe e al.
12
. Tha
sys em consis ed in soaking il e pape in a 1.0% w solu ion o polys y ene in oluene o 2h
and hen d ying a oom empe a u e o 15 minu es. This u ned he pape , which is hyd ophilic,
in hyd ophobic. Then, a hyd ophilic pa e n was e ched by he ejec ion o oluene d ople s,
which dissol ed he hyd ophobic polyme ma e ial. The dissol ed excess polyme was
accumula ed a he ou side o he liquid d ople s acco ding o he co ee ing e ec upon oluene
e apo a ion and aken up by he su ounding pape . Doing his, he pape became hyd ophilic
again, almos exac ly as a he beginning. Once he hyd ophilic channel had been c ea ed,
senso eagen s could be p in ed using inkje p in ing echnology, oo. Using his me hod,
mul iple analy e senso s can be done. Howe e , his sys em has been c i icized due o he isk
ha some hyd ophobic polyme emained in he hyd ophilic pa e n, since a he beginning all
he pape was soaked.
6
In igu e 1, a schema ic ep esen a ion o he sys em used by Abe e al. o make mul ianaly e
senso s is shown.
Figu e 1. Schema ic ep esen a ion o he sys em used by Abe e al. o make mul ianaly e
senso s. Sou ce: Abe e al., 2008
12
The main p oblem o his sys em was he co ee ing e ec ha ook place when he analy e
eached he senso . The analy e pushed he sensing eagen s o he sensing a ea limi s,
esul ing in a non homogeneous colou , which made di icul o ake ou aluable in o ma ion o
he expe imen s. In igu e 2, an ou line desc ibing he co ee ing e ec consequences can be
obse ed.
Figu e 2. Ou line showing he co ee ing e ec consequences
In igu e 3, he senso eagen can be obse ed be o e and a e applica ion o he analy e. The
e ec s o co ee ing e ec can be obse ed, oo.
Figu e 3. Senso eagen in di e en sensing a eas, be o e (pa e ns numbe ed wi h “1”) and
a e (pa e ns numbe ed wi h “2”) analy e applica ion. Sou ce: Abe e al., 2008
12
7
3. Expe imen al sec ion
3.1. P epa a ion o he pa e ns
The sys em p oposed o make pa e ns p oposed by Abe e al.
12
used oluene, which is
an
en i onmen and heal h a ec ing ola ile o ganic sol en (VOC) ha equi es some secu i y
measu es when i is used. Mo eo e , i had he p oblem ha he analy e lowed o a pa h whe e
p e iously a polyme had been p in ed. Despi e polys y ene was emo ed using oluene, which
apo izes easily, some con amina ion may occu , leading o inco ec esul s. So, a new me hod
o c ea ing pa e ns was used, which consis ed basically in p in ing he hyd ophobic ba ie only
in he pa s equi ed o be hyd ophobic. Doing his, he hyd ophilic pa whe e he analy e had o
low emained unchanged, no isk o con amina ion exis ed, and oluene was no used.
The eagen s used o c ea e he hyd ophobic ba ie we e changed, oo. One o he eagen s
used p e iously was oluene, bu low apo iza ion empe a u e sol en s a e no desi ed
eagen s in he indus y ield, since hey a e conside ed dange ous. So, ins ead o he oluene
and polys y ene solu ion, a solu ion o Oc adecyl Ac yla e, 1,10-Bis(ac yloyloxy)decane and 2,2-
Dime hoxy-2-phenylace ophenone, which was used as ini ia o , we e used.
Once he solu ion was p in ed, i was polyme ized using ul a iole ligh (Hamama su Ligh ning
Cu e 6686). In all he expe imen s 600 mW/cm
2
we e used. I mus be aken in o accoun ha
once his solu ion was p in ed, i sp ead e y as , so UV ligh mus be applied immedia ely a e
p in ing. I some ime was awai ed be ween p in ing and polyme iza ion, sp ead o he ink would
be p oduced, and when i was polyme ized, he pa e n would ge a di e en o m om he
o iginal, causing symme y and low p oblems.
I mus be aken in o accoun ha he hyd ophobic ba ie p in ing p ocedu e consis ed in wo
s eps, since he on pa and he back pa o he subs a e we e polyme ized independen ly.
The back pa o he pa e n was o ally co e ed by he hyd ophobic ba ie , o p e en he
senso eagen and he analy e om leaking ou side he pa e n.
Once he hyd ophobic pa e n had been p in ed, he senso eagen could be p in ed in he
desi ed zone o he pa e n. Once bo h he hyd ophobic ba ie and he senso eagen we e
p in ed, analy e was d opped in o he pa e n and some ime la e colou change was analysed
using a colou de ec ion so wa e (Digi al Colo Me e so wa e Ve . 3.6.1 p o ided wi h he Mac
OS X Ve . 10.5 ope a ing sys em).
The subs a e used o c ea e he pa e ns was il e pape (Ad an ec 5C 185mm). The subs a e
used mus be abso ben and esis an o UV ligh .
8
In Figu e 4, a schema ic ep esen a ion o he p epa a ion o he pa e ns is shown.
Figu e 4. Rep esen a ion o he p epa a ion o he pa e ns
3.2. P epa a ion o he hyd ophobic ink
As i was old be o e, he solu ion used o c ea e he hyd ophobic ba ie consis ed o Oc adecyl
Ac yla e (ODA, p o ided by WAKO), 1,10-Bis(ac yloyloxy)decane (DDA, p o ided by Tokyo
Chemical Indus ies) and 2,2-Dime hoxy-2-phenylace ophenone (p o ided by WAKO), which
was used as ini ia o . To p epa e i , a solu ion o ODA and DDA (ODA-DDA, 70-30 %w ) was
p epa ed, and la e ini ia o was added o he solu ion (ODA:DDA-ini ia o , 85-15 %w ). Then,
some s i ing ime was applied.
This solu ion showed good pe o mances a sho ime e m, bu a e some days he pa e n
pe o mances clea ly wo sened. In o de o imp o e he pa e n du abili y, he s abilize o ODA
and DDA can be emo ed.
To emo e he ODA s abilize , i was mixed in an e hanol and 5% w NaOH solu ion, and i was
submi ed o a sepa a ion p ocess. A e he sepa a ion p ocess, dis ille and a acuum bomb
we e used o e apo a e he emaining e hanol. In he case o DDA, he p ocess was he same,
bu no e hanol was used.
3.3. P epa a ion o he pH senso
Two pH senso s we e used in his p ojec , one made o pa icles and ano he one wi hou hem.
In he i s expe imen s made wi h pH senso s, he pa icle based sensing eagen was used,
since he capaci y o pa icles o ge s uck o he pape made i mo e esis an o he co ee ing
e ec . Howe e , i has been demons a ed ye ha co ee ing e ec can be a oided using pH
based pa icle sensing eagen e en wi h he simples pa e ns ( he ones wi h only an analy e
en ance, such as he “Simple es ” se ies pa e ns). P epa a ion me hod o his eagen is
explained by Abe e al.
11
Non pa icle pH sensing eagen , which is mo e easily a ec ed by he co ee ing e ec han he
p e ious one, was used o demons a e ha mul iple pa h channels can a oid i . P epa a ion
me hod o his sensing eagen is explained by Abe e al.
12
Back
pa e n
p in ing
UV ligh
polyme iza ion
15
Figu e 11. Ou line o ink sp ead and i s esis ance depending on he pa h wid h
I also seems logic ha he ink esis ance is he main p oduce o he analy e low asymme y,
so in wide pa hs, less asymme y exis ed. Al hough i is ue ha pape does no possess an
homogeneous s uc u e and i p obably causes low asymme y, i is hyd ophilic and he analy e
can low h ough i , while monome ink is hyd ophobic and he pa s o he pa h in aded by i
canno be c ossed by he analy e anymo e, p oducing an impo an e ec in e ms o low
asymme y. Looking a able 4, his ac is checked, since he wide he pa h is, he less delay
be ween lows occu ed.
Rega ding he polyme iza ion ime, despi e ime di e ences could be no iced on he same
pa e n depending on he polyme iza ion ime applied, no ela ion be ween he polyme iza ion
ime and e ec s in low eloci y and symme y could be es ablished. I mus also be aken in o
accoun ha expe imen s ep oducibili y was e y low and s anda d de ia ion alues con i m i .
This poo ep oducibili y makes di icul o es ablish empi ical ela ions. Ob iously, an impo an
ac o ha a ec s se iously he ep oducibili y o he expe imen s is he p in e used. EPSON is
a low cos comme cially a ailable p in e , and he hyd ophobic ink used p obably p oduces
pa ial clogging o he nozzles, leading o di e ences in he dispensed amoun s o ink.
No expe imen s in ol ing senso eagen s we e done, since he pe o mances o he pa e ns
designed was no sa is ac o y enough.
To check he pa e ns pe o mance du abili y made wi h monome ink wi h s abilize , ha needs
mo e polyme iza ion ime bu has a lowe a e age li e han wi hou s abilize , some pa e ns
we e es ed again an hou la e . In able 5, pa e ns low imings obse ed a e polyme iza ion
and an hou la e can be obse ed.
Pa e n Name-da e Polyme iza ion
ime Leaki
ng
1
(s)
2
(s)
delay
(s)
senso
a ea (s)
1-2/5/2011 1 min/pp No 65 87 22 160
1'-2/5/2011 1 min/pp No 20 38 18 90
C_s3w03ch15_
sho pa h+ (a e
polyme iza ion) 3'-2/5/2011 2 min/pp No 83 83 0 220
1-2/5/2011 1 min/pp No
1'-2/5/2011 1 min/pp No 28 38 10 70
C_s3w03ch15_
sho pa h+ (an hou
la e ) 3'-2/5/2011 2 min/pp No 40 55 15 165
2-2/5/2011 1 min/pp No 80 310
230 330
C_s3ci 3w03ch15_
sho pa h+ (a e
polyme iza ion) 4-2/5/2011 2 min/pp No 150
210
60 270
2-2/5/2011 1 min/pp No 80 240
C_s3ci 3w03ch15_
sho pa h+ (an hou
la e ) 4-2/5/2011 2 min/pp No 79 170
91 330
Table 5. E ec o ime on pa e ns pe o mance made o monome ink wi h s abilize compa ing
hei low beha iou s jus a e polyme izing and an hou la e

16
Compa ing he i e pa e ns es ed i can be obse ed ha in all cases he esul s changed
signi ican ly, pa ly due o bad ep oducibili y, and in mos o hem, pa e ns pe o mance
wo sened, becoming he pa hs blocked in some cases. So, wi h hese expe imen s i can be
concluded ha pa e ns du abili y using monome ink wi h s abilize is low. This was aken in o
accoun in ollowing expe imen s when he pa e ns es ing was no p oduced jus a e
polyme iza ion, using in hese cases monome ink wi hou s abilize .
4.3. Fou pa h pa e ns
In his sec ion, esul s ob ained using pa e ns om numbe 16 o 25 a e analysed. Amos all
hese pa e ns geome y consis ed o wo a eas connec ed by wo symme ical pa hs ha
bi u ca ed in o wo mo e pa hs, esul ing in ou symme ical pa hs ha en e ed he senso
eagen a ea. The idea o designing ou pa hs is o su ound he senso eagen a ea mo e
e ec i ely han wi h he wo pa hs pa e ns, eaching a be e low cancella ion and
consequen ly, educing he co ee ing e ec . Ob iously, hese pa e ns we e designed aking
in o accoun he conclusions o he p e ious sec ion.
4.3.1. Pa e ns 16 o 21
The i s pa e ns es ed was pa e n numbe 16 and 17 (C_s3ci 3w03ch15_sho pa h4 and
C_s3w03ch15_sho pa h4), which we e p in ed using EPSON p in e and whose geome y can
be obse ed in igu e 12. This pa e n consis ed o a 3 mm side d opping squa e and 3 mm
diame e senso eagen a ea. Channel wid h was 1.5 mm, and he bi u ca ed pa hs wid h was
0.75 mm.
Figu e 12. C_s3ci 3w03ch15_sho pa h4 pa e n geome y
Deionized wa e could no low h ough he bi u ca ed pa hs, since hei wid h (0.75 mm) was
oo na ow o le wa e pass, and wa e became blocked o i lowed ex emely slowly.
Nex pa e ns designed we e pa e ns 18, 19 and 20. The basic di e ence wi h he p e ious
ones was a wide pa h (18 o 30 mm) o bo h he main pa hs and he bi u ca ed ones. The
pa hs geome y was changed o a cu ed shape, expec ing o ge be e lowing pe o mances
han wi h angula shapes. Howe e , se ious leaking and blocking p oblems appea ed, being
almos impossible o he low o each he senso eagen a ea, independen ly o he deionized
wa e olume applied (10 o 60 µl) o he polyme iza ion ime (1 o 4 minu es o e e y pa o
he pape ).
The cause o hese p oblems was he polyme iza ion me hod used. The pa e ns o his sec ion
we e so wide ha he UV ligh could no su ound all he pa e n p ope ly, causing an insu icien
and inhomogeneous polyme iza ion. So, o polyme ize all he nex expe imen s o his sec ion,
he UV ligh was ocused al e na i ely on di e en pa s o he pa e n in a symme ic way, in
o de o assu e ha all pa s o he pa e n go polyme ized in he same way. An ou line o he
di e en ways o polyme ize he pa e ns can be obse ed in igu e 13.
17
Figu e 13. Ou line o he di e en me hods o polyme ize wide pa e ns
4.3.2. Pa e n C_s3s4w1ch24_c _ch04_18_ sho pa h4
To check his polyme iza ion me hod, pa e n numbe 21 (C_s3s4w1ch24_c _ch04_18_
sho pa h4) was p in ed and es ed wi h 20 µl o bo h deionized wa e and ed dye.
Polyme iza ion ime o e e y pa o he pa e n was 3 min, al hough e e y pa o he pa e n
was no polyme ized o 3 minu es, since as i was old be o e he UV ligh ocus posi ion was
changed al e na i ely. EPSON p in e was used.
In o de o ha e a be e and as e polyme iza ion, om his ime on in he expe imen s o his
sec ion, monome ink used had been pu i ied, emo ing he s abilize acco ding o he me hod
explained in 3.2.P epa a ion o he hyd ophobic ink.
In able 6, C_s3s4w1ch24_c _ch04_18_ sho pa h4 expe imen s esul s can be obse ed. In
igu e 14, C_s3s4w1ch24_c _ch04_18_ sho pa h4 pa e n geome y and he di e en pa e n
zones nomencla u e a e shown.
Name-da e Tes
subs ance Leaking
A (s)
A1
(s) A2
(s) B (s)
B1
(s) B2
(s) C (s)
25-3/6/2011 Dye No 10 25 25 19
25'-6/6/2011 Dye No 2 13 14 42
25''-6/6/2011 Dye No 16 34 53 97
26-3/6/2011 Deionized
wa e No 164 390 390 86 312 312 420
26'-6/6/2011 Deionized
wa e No 20 48 48 96 99
26''-6/6/2011 Deionized
wa e No 45 153 150 83 390
Table 6. C_s3s4w1ch24_c _ch04_18_ sho pa h4 pa e ns es esul s
Figu e 14. C_s3s4w1ch24_c _ch04_18_ sho pa h4 pa e n geome y and i s zones
nomencla u e
18
Compa ing C_s3s4w1ch24_c _ch04_18_ sho pa h4 and he p e ious ou pa h pa e ns
polyme ized wi h he inhomogeneous me hod, i can be obse ed ha pa e n pe o mances
we e clea ly be e . To begin wi h, no leaking p oblems we e de ec ed, and blocking and
ine icien low anspo p oblems we e educed conside ably. Howe e , in wo o he pa hs
analysed, he analy e lowed so slow ha did no each he bi u ca ion, and in ou cases i did
no a i e o he senso eagen a ea, so his pa e n is s ill e y ine icien in e ms o analy e
lowing.
I is ema kable ha in pa e ns which dye was used as analy e, he low was conside ably
as e han he ones which used deionized wa e . This esul is in e es ing, since i means ha
some subs ance p ope ies, such as su ace ension, may a ec he lowing p ope ies o
pa e ns. So, i would be in e es ing o do some u u e esea ch in his ield.
In igu e 15, pa e n 25-3/6/2011 can be obse ed.
Figu e 15. C_s3s4w1ch24_c _ch04_18_ sho pa h4 pa e n es ed wi h ed dye. No eal
dimensions
4.3.3. Pa e n C_s45s4w1ch24_c _ch04_18_sho pa h4
This pa e n design is simila o he p e ious one, bu he d opping squa e is bigge (4.5 mm),
allowing o d op mo e han 20 µl o analy e. In he nex se ies o expe imen s, pa icle based pH
senso eagen , whose syn hesizing me hod is explained a Abe e al.
13
, was p in ed in o he
cen e o he senso eagen a ea.
EPSON p in e was used o p in he pa e ns and analy e used was a pH 12 NaOH solu ion.
Polyme iza ion ime was 3 min.
The senso eagen was p in ed wi h Dima ix. Ca idge se ing used was
pH_indica o _pa icle_ca idge. Senso eagen geome y was 3x3 mm
2
squa e, and di e en
p in ing laye s we e es ed.
19
In able 7, C_s45s4w1ch24_c _ch04_18_ sho pa h4 expe imen s esul s can be obse ed.
Name-da e
Volume o analy e
(µl)
P in ing laye s
A
(s) A1
(s) A2
(s) B
(s)
B1
(s) B2
(s) C (s)
Tes Obse a ions
29-
13/6
/201
1
30 1 15 21 21 10
15 15 26 No colou emained. Weak
colou
30-
13/6
/201
1
20 1 15 22 22 35 Reagen was sp ead o he igh
side and bi u ca ed pa hs.
Weak colou
31-
13/6
/201
1
20 1 49 110
79 48
114
96 Senso shape was modi ied.
Weak colou
32-
14/6
/201
1
20 10 42 17
29 29 Reagen was sp ead o he le .
Inhomogeneous colou
33-
14/6
/201
1
20 15 24 48 48 40
86 100
Colou change only in some
pa o he senso squa e
34-
14/6
/201
1
30 15 12 19 19 Reagen was sp ead o he
igh . Inhomogeneous colou
35-
14/6
/201
1
30 15 15 21 21 23
32 32 Inhomogeneous colou
Table 7. C_s45s4w1ch24_c _ch04_18_ sho pa h4 pa e ns es esul s
Figu e 16. C_s45s4w1ch24_c _ch04_18_ sho pa h4 pa e n geome y and i s zones
nomencla u e
Analysing he esul s, i can be obse ed ha only one p in ing laye is such a li le amoun o
senso eagen , and consequen ly he colou change ob ained was so weak ha may no be
de ec ed by colou de ec ion so wa e o he quan i y used was so li le ha i was washed by
he analy e and disappea ed. O he wise, and independen ly o he p in ing laye s p in ed,
inhomogeneous colou and senso eagen sp eading occu ed, p obably due o low
asymme y. So, hese expe imen s p o ed ha low asymme y mus be e adica ed in o de o
a oid co ee ing e ec and ob ain a homogeneous colou change.
20
Simila ly o expe imen s pe o med in able 6, pH 12 NaOH solu ion lowed as e han
deionized wa e solu ion. Causes o his phenomena may be he same as o dye solu ion.
Mo eo e , in his case basici y may be an impo an pa ame e , oo.
No leaking was obse ed in any o he pa e ns.
In o de o imp o e pa e ns pe o mances and a oid he low asymme y, mo e
C_s45s4w1ch24_c _ch04_18_ sho pa h4 we e p in ed using EPSON p in e , and di e en
polyme iza ion p ocedu es we e applied.
In p e ious expe imen s, i was no iced ha pa e ns de o med a bi when hey became we , and
his de o ma ion may enhance low asymme y. In o de o sol e his p oblem, he zone a ound
he pa e ns was s icked wi h adhesi e ape o he su ace whe e he expe imen s we e being
conduc ed. Howe e , pa e ns s ill ben a bi .
To p in he pa e ns, all o hem we e p in ed one by one and polyme ized, and hen es s o he
pa e ns we e conduc ed. So, i mus be aken in o accoun ha he e we e ime di e ences
be ween polyme iza ion and es s o he pa e ns, al hough hey we e no signi ica i e (no mo e
han 30 minu es). Deionized wa e was used o pe o m he es s.
4 polyme iza ion me hods we e es ed:
1) Each side o he pape was polyme ized o 3 minu es wi h 600 mW UV ligh . On each side o
he pape , polyme iza ion was conduc ed in wo zones, changing om one zone o he o he
e e y 5s du ing he i s 20s, and changing e e y 10s om hen.
2) Each side o he pape was polyme ized o 3 minu es wi h 600 mW UV ligh . On each side o
he pape , polyme iza ion was conduc ed in wo zones, changing om one zone o he o he
e e y 5s.
3) Each side o he pape was polyme ized o 6 minu es wi h 300 mW UV ligh .
4) Each side o he pape was polyme ized o 3 minu es wi h 300 mW UV ligh .

21
In able 8, expe imen s pe o med wi h each me hod can be obse ed. Expe imen s in o ange
we e made and es ed wi h a day di e ence. C_s45s4w1ch24_c _ch04_18_ sho pa h4 pa e n
geome y and i s zones nomencla u e can be obse ed a igu e 16.
Polyme iza ion
me hod Name-da e Volume o
analy e (µl)
A (s)
A1
(s) A2
(s) B
(s) B1
(s) B2
(s) C (s)
PT1-
16/6/2011 30 308 1080 1080 310 848 780 1200
PT1'-
16//2011 30 440 680 380 820 900
PT1d1-
21/6/2011 30; a e 25'
30µl mo e 400
1
PT1'd1-
21/6/2011 30; a e 25'
30µl mo e 1950 1860
PT1''-
16/6/2011 30 33 42 42 69
PT1'''-
16/6/2011 30 270 270
PT1''d1-
21/6/2011 30; a e 25'
30µl mo e 590 1680 1320 810 1740
1740
1890
2
PT1'''d1-
21/6/2011 30; a e 25'
30µl mo e 1680
PT2-
16/6/2011 30
PT2'-
16//2011 30 160 400 510 230
PT2d1-
21/6/2011 30; a e 25'
30µl mo e
3
PT2'd1-
21/6/2011 30; a e 25'
30µl mo e
PT3-
16/6/2011 30 150 360 360 150 360 360 460
PT3'-
16//2011 30 80 120 120 210
PT3d1-
21/6/2011 30; a e 25'
30µl mo e 420 1860 960
4
PT3'd1-
21/6/2011 30; a e 25'
30µl mo e 420 1500 1080 1020
2040
1980
2220
Table 8.
C_s45s4w1ch24_c _ch04_18_ sho pa h4
pa e ns es esul s using di e en
polyme iza ion me hods
The wo s esul s we e ob ained wi h me hod 3), so i may be concluded ha an excessi e ime
o polyme iza ion will lead o unsa is ac o y pe o mances.
The o he polyme iza ion me hods showed so dispe sed esul s ha p ope conclusions could
no be made. Resul s we e no ep oducible and hey showed in some cases ex emely
asymme ic speed low esul s.
The same pa e ns we e made again, and a day be ween polyme iza ion and es wi h deionized
wa e was le . Resul s (which a e ma ked wi h o ange in able 8) showed wo se pe o mances
and ep oducibili y han he p e ious ones. Ac ually, esul s we e so unsa is ac o y ha mo e
deionized wa e had o be d opped a e 25 minu es o es ime due o he low pe o mances
ob ained. Al hough i is possible ha ime in luences pa e n pe o mances, hese esul s could
be a consequence o he p in ing condi ions, since EPSON p in e is a come cially a ailable
p in e and p obably he amoun o ink dispensed was changing.
22
In conclusion, pa e ns p e iously designed could no p o ide symme ic lows, so i is no
possible o analyse any analy e pa ame e wi h hese pa e ns, since co ee ing e ec canno
be a oided.
In o de o s udy mo e in de ail he e ec o basic solu ions on he pa e ns, he ollowing
expe imen was conduc ed. Pa e ns PT1d1 and PT2d1, which had been es ed wi h deionized
wa e , we e es ed wi h pH 12 NaOH solu ion once deionized wa e had been apo ized. And
once NaOH solu ion apo ized, deionized wa e was applied again. Resul s can be obse ed in
able 9.
Polyme iza ion
me hod
Name-da e
Analy e
Volume o
analy e (µl)
A
(s) A1
(s) A2
(s) B
(s) B1
(s) B2
(s) C
(s)
Deionized
wa e
30;
a e
25'
30µl
mo e
400
NaOH
(pH 12) 30 24 34 34 57 50
2 PT1d1-
21/6/201
1
Deionized
wa e 30 26 34 34 41 52
Deionized
wa e
30;
a e
25'
30µl
mo e
NaOH
(pH 12) 30 30 60 70 70 95 97
3 PT2d1-
21/6/201
1
Deionized
wa e 30 86 98 98 91 111 111 115
Table 9.
C_s45s4w1ch24_c _ch04_18_ sho pa h4
pa e ns es esul s using di e en analy es
Obse ing he esul s ob ained, i can be obse ed ha pH 12 NaOH solu ion lowed ex emely
as e han he deionized wa e one. Howe e , when deionized wa e was d opped again, i
lowed as as as NaOH solu ion. This may mean ha basic solu ions can dilu e polyme ink
con amina ion ha loca es in he pa h o educe somehow he pa h esis ance. Howe e , i
exis s he possibili y ha some NaOH con amina ion emained in he pape . Fu u e esea ch
could be ocused on his phenomena unde s anding.
4.3.4. Pa e n C_s45s4w1ch24_c _ch04_18_sho pa h4_sex 9
Finally, pa e n C_s45s4w1ch24_c _ch04_18_sho pa h4_sex 9 was designed. This pa e n is
simila o he p e ious one, bu an addi ional 9x9 mm
2
d opping squa e was made and
connec ed wi h he p e ious d opping wa e squa e. The basic idea was, on one hand, o c ea e
an a ea o d op a la ge quan i y o analy e in o de o su pass he pa h esis ance and on he
o he hand o d op he analy e in a zone which was no he zone whe e pa hs ge di ided.
I he d opping squa e is he same squa e whe e pa hs begin, i is possible ha low does no
dis ibu e homogeneously in i depending on he exac d opping posi ion, which is clea ly
in luenced by human e o , and consequen ly lowing di e en wa e quan i ies on each pa h,
which will p oduce low asymme y. Howe e , i analy e is d opped in ano he a ea, when
analy e a i es a he bi u ca ion a ea, analy e dis ibu ion will be mo e symme ic. Figu e 17 has
been c ea ed o explain i in mo e de ail.
23
Figu e 17. Ou line ep esen ing analy e dis ibu ion depending on pa e n geome y
Some pa e ns C_s45s4w1ch24_c _ch04_18_sho pa h4_sex 9 we e es ed, bu no sa is ac o y
esul s we e achie ed. Al hough a lo o wa e was d opped (un il 400 µl), i emained in he big
d opping squa e and only a li le pa lowed, so he esul s ob ained we e he same as
C_s45s4w1ch24_c _ch04_18_ sho pa h4 esul s, whe e blocking, low asymme y and low
lowing pe o mances occu ed.
Howe e , he idea o ha ing a d opping squa e and a sepa a e pa h bi u ca ion zone was used
in u u e pa e ns.
In igu e 18, a es ed C_s45s4w1ch24_c _ch04_18_sho pa h4_sex 9 pa e n can be obse ed.
Figu e 18. C_s3s4w1ch24_c _ch04_18_ sho pa h4 pa e n es ed wi h ed dye. No eal
dimensions
4.4. Simple symme y pa e ns
In o de o sol e he asymme y p oblems, a new se ies o pa e ns we e made. All he
geome y ips lea ned om he p e ious sec ions we e applied. Fo example, he d opping a ea
and he pa h bi u ca ion a ea we e loca ed in di e en zones.
To enhance low symme y, pa e ns designed could be polyme ized wi hou changing he UV
spo ligh posi ion. In o he wo ds, all he pa e ns designed could be loca ed in a 20 mm
diame e ci cum e ence, which is he UV spo ligh diame e . I mus be aken in o accoun ha
changing he UV spo ligh posi ion p oduces polyme iza ion inhomogenei y, since cen al pa s
o he pa e n ge mo e polyme ized han ou e pa s, and i is no possible o mo e he spo ligh
manually loca ing i in he same posi ion all ime. Apa om educing he pa e ns size o be
polyme ized a once, pa hs we e made as big as possible, in o de o educe he ink sp ead
e ec s in he low.
24
This sec ion expe imen s we e pe o med using monome ink wi hou s abilize .
4.4.1. Pa e n Simple symme y 1
To begin wi h, Simple symme y 1 pa e n was designed. This pa e n design is he simples one,
and i is e y simila o Simple es pa e n se ies, bu bo h d opping, senso eagen squa es
and pa hs dimensions we e bigge . In igu e 19, Simple symme y 1 geome y is shown.
Figu e 19. Simple symme y 1 pa e n geome y
In igu e 20 a es ed Simple symme y 1 pa e n can be obse ed.
Figu e 20. Simple symme y 1 pa e n es ed wi h ed dye. No eal dimensions
The eason o do his pa e n was o check ha a pa e n wi h he polyme iza ion condi ions
(wi hou mo ing he spo ligh ) and pa h dimensions commen ed be o e would be able o each
sa is ac o y low symme y pe o mances. These pa e ns we e p in ed wi h EPSON p in e and
polyme ized o h ee minu es. 20 µl o deionized wa e we e used o do he es s. Resul s can
be obse ed a able 10, whe e ime equi ed o he analy e o each he opposi e squa e is
shown.
Name-da e
Time o each he senso a ea
(s)
Name-da e
Time o each he senso a ea
(s)
39-
23/6/2011 3
44-
23/6/2011 135
40-
23/6/2011 2
45-
23/6/2011 4
41-
23/6/2011 9
46-
23/6/2011 8
42-
23/6/2011 9
47-
23/6/2011 69
43-
23/6/2011 4
Table 10. Simple symme y 1 pa e n es esul
Al hough wo abno mal esul s we e ob ained, he es we e qui e simila and ep oducible.
Once checked his pa e n low pe o mance was sa is ac o y, wo pa h pa e ns we e designed
in o de o check he low symme y.
4.4.2. Pa e n Simple symme y 2 and Simple symme y 3
Nex pa e n designed was Simple symme y 2. This pa e n geome y consis ed o a d opping
squa e and wo senso eagen squa es. The eason o make his pa e n was no o p in wo
senso eagen s, bu checking he pa e n low symme y o his kind o pa e n.
This pa e n es esul s a e shown a able 11. In he es 20 µl o deionized wa e we e used
and a polyme iza ion ime o 3 minu es was applied.
31
o measu e analy es p ope ies wi h he sys em s udied in his p ojec . The p ocedu e o c ea e
he di e en pH bu e solu ions used a e speci ied a sec ion 3.4 (P epa a ion o he pH bu e s).
The analy e amoun used in he pa e ns was 12 µl, excep in pa e n 106, ha needed 23µl.
Be o e and a e doing he pa e ns es s, hey we e scanned in o de o de ec he senso
eagen colou digi ally (Digi al Colo Me e so wa e Ve . 3.6.1 p o ided wi h he Mac OS X Ve .
10.5). The colou de ec ion sys em used was he L*a*b* sys em, and he pa ame e used o
analyse he colou di e ence was a*, since he mos impo an colou change occu ed in he
ed onali y. Mo eo e , in o de o check he ela ion be ween colou change and ime, pa e ns
we e scanned be o e es ing and a di e en imes a e es ing. In Annex III. Simple symme y 6
(made wi h EPSON and Dima ix) pa e ns using non pa icle pH based senso eagen . Colou
and image da a pa e ns colou da a, as well as hei images, can be obse ed.
Obse ing all pa e ns colou da a be o e being es ed, i can be no iced ha he p in ing
ep oducibili y was so high, and he ini ial a* alues we e e y simila , being he a e age alue
15.782 and he s anda d de ia ion 0.671. So, in o de o analyse he colou change, only he
es ing a* alue mus be aken in o accoun , since he ini ial a* alue was app oxima ely he
same o all he pa e ns.
Looking a he esul s, i can also be obse ed ha he colou alues depended on ime. The
mos ep oducible and cohe en esul s we e ob ained, app oxima ely, be ween 10 and 25
minu es a e he es . I is logical ha some ime is equi ed o le he low each all he analy e
laye s and ha a e some ime he pH senso eagen may be a ec ed by o he ac o s ha
may in e e e in he colou change, such as i s dilu ion in o he analy e. Mo eo e , depending on
he pH bu e , di e en imes we e equi ed o change he colou , so, al hough he op imal
colou da a was ob ained be ween 10 and 25 minu es, depending on he case hese ime lapse
may be sligh ly modi ied.
In igu e 29, a calib a ion cu e ela ing he colou and he pH can be obse ed. As i was
commen ed p e iously, he alues used o do i we e aken be ween 10 and 25 minu es a e
he es .
-5
0
5
10
15
20
56789
pH
a*
Figu e 29. Calib a ion cu e co ela ing he colou da a ob ained using pH bu e solu ions in
Simple symme y 6 pa e ns
A good calib a ion cu e wi h so li le e o could be c ea ed. The e o ba s indica e he
samples s anda d de ia ion alues (4 samples we e pe o med o e e y pH bu e ). Howe e , i
mus be aken in o accoun ha only wo o he ou expe imen s made wi h pH 7 bu e we e
used, since he es showed e y di e en alues.
Rega ding co ee ing e ec , i could be a oided in a g ea quan i y o he pa e ns es ed.
Howe e , some o hem showed some, since he low symme y ob ained was no pe ec ,
pushing away he senso eagen in some cases. This is no a se ious p oblem, since he co ee
ing e ec p oduced in hese cases was no p onounced a all and i did no a ec he esul s.

32
In conclusion, he c ea ion o his calib a ion cu e demons a es ha wo pa hs pa e ns a e a
easible me hod o de ec analy e p ope ies, a oiding o a la ge deg ee he co ee ing e ec
and p o iding so exac esul s.
4.4.5.2. Tes using only EPSON
Once i was demons a ed ha wo pa h channels a e a easible and use ul ool, he same
expe imen was done again, in he same condi ions, bu his ime using only EPSON p in e . In
o he wo ds, he senso eagen was p in ed using EPSON p in e .
The sensing eagen zone dimensions we e he same han in he p e ious expe imen , as well
as he in e laye p in ing ime. Howe e , he numbe o laye s p in ed was changed o 10 laye s,
ins ead o 15.
As i can be obse ed in Annex IV. Simple symme y 6 (made only wi h EPSON) pa e ns using
non pa icle pH based senso eagen . Colou and image da a
,
EPSON esul s showed a good
ep oducibili y. Fo example, he s anda d de ia ion alue o he senso eagen colou da a (a*)
be o e being es ed was 0.97, which is simila o he esul ob ained when Dima ix was used in
he p e ious expe imen (0.67). Mo eo e , colou da a alues we e almos simila , being 15.78
when Dima ix was used and 15.09 when EPSON was used.
In igu e 30, he calib a ion cu e ob ained wi h he di e en pH alues can be obse ed.
Figu e 30. Calib a ion cu e co ela ing he colou da a ob ained using pH bu e solu ions in
Simple symme y 6 pa e ns. Only EPSON p in e was used.
As i can be obse ed, esul s we e so ep oducible, and s anda d de ia ion alues we e
accep able in all cases, al hough in pH 7 and 8 he s anda d de ia ion alues we e highe han
in he p e ious expe imen . I mus be aken in o accoun ha in some cases co ee ing e ec
appea ed, as i can be obse ed in igu e AIV6 o Annex IV. Simple symme y 6 (made only wi h
EPSON) pa e ns using non pa icle pH based senso eagen . Colou and image da a, and in
some o hese cases he colou de ec ion zone was mo ed om he o iginal sensing eagen
zone, in o de o achie e mo e eliable esul s.
33
I mus be aken in o accoun ha o his expe imen new non pa icle based pH senso eagen
was done, so colou da a ob ained o he di e en pHs a ied om he ones ob ained in he
p e ious expe imen .
In conclusion, in his las expe imen i was demons a ed ha i is possible o de ec
quan i a i ely a subs ance p ope y, like pH, using only a comme cially a ailable p in e o p in
he eagen s, making mo e easible he possibili y o using and c ea ing his kind o sensing
sys em in he same place whe e i is equi ed. Al hough in his case he senso eagen used
was a pH senso eagen , i could be used wi h o he kinds o senso eagen s, oo.
5. Conclusions
The main goal o his p ojec was o de elop a sensing sys em ha was able o de ec analy es
o analy e p ope ies wi hou he necessi y o ei he quali ied p o essionals o sophis ica ed
equipmen . This goal has been achie ed, since a sensing de ice was c ea ed using a
comme cially a ailable p in e , an UV ligh , a scanne and a simple colou de ec ion so wa e.
The sys em designed was p o ed using a pa icle and a non pa icle based pH sensing eagen ,
and o bo h o hem a calib a ion cu e ela ing pH alues and senso eagen colou da a we e
pe omed. Mo eo e , he sys em designed is no only limi ed o pH senso eagen s, and mo e
senso eagen s may be used, since he sys em is e sa ile, accep ing e en he use o aqueous
(non pa icle based) eagen s, oo.
A be e comp ehension o he ink sp ead e ec and i s consequences was ob ained. Ink sp ead
was he main cause o assyme y in he pa e ns, since hyd ophobic ink in ades he hyd ophilic
pa h in an i egula way, p oducing i egula low esis ance, which is inc eased eno mously
when he pa h is leng hened. So, in e es ing pa e n design ips, such as he mos sui able
polyme iza ion condi ions, we e lea ned in o de o a oid assyme y and pa h esis ance.
I was also demons a ed ha wo pa h and ou pa h channels a e easible me hods o educe
low asymme y, and consequen ly he co ee ing e ec p oduced when he analy e washed
away he senso eagen .
6. Fu u e esea ch
In his p ojec a sensing sys em was p esen ed, bu i was only es ed wi h pH sensing eagen .
Howe e , one o he p ojec aims was o c ea e a sensing de ice as uni e sal as possible, so
mo e sensing eagen s should be es ed.
Pa e ns design could be imp o ed in o de o imp o e pa e ns pe o mances. Fo example, a
ou pa h channel may be designed using he Simple symme y pa e ns design c i e ia. This
new design may be able o educe he co ee ing e ec .
I was obse ed ha depending on he analy e used, low eloci y changed. I was also
obse ed ha he mo e basic o acid he analy e pH was, he as e i lowed, while he mo e
neu al, he slowe i lowed. I would be in e es ing o check which a e he ac o s ha p oduce
his phenomena, as well as checking i he pape s uc u e was modi ied.
Finally, i would be in e es ing o modi y he pa e ns c ea ed in o de o c ea e mul ianaly e
sensing de ices, such he one showed in igu e 31.
34
Figu e 31. Mul ianaly e sensing pa e n designed using he
Simple symme y pa e ns design c i e ia
7. Acknowledgemen
I would like o hank Daniel Ci e io (Mas e ’s Thesis ad iso ), Imo o Sho a and Maejima Ken o
o he assis ance and ad ice p o ided, and o Suzuki Koji o le ing me o do he p ojec in he
labo a o y he di ec s.
8. Bibliog aphy
[1] Ma inez, A.W. e al. Diagnos ics o he de eloping wo ld: mic o luidic pape -based
analy ical de ices. Analy ical Chemis y 82(1), 2010.
[2] Ma inez A.W. e al. Flash: a apid me hod o p o o yping pape -based mic o luidic de ices.
Lab on a Chip [www. sc.o g/loc].
[3] Ma inez A.W. e al. Th ee-dimensioanl mic o luidic de ices abica ed in laye ed pape and
ape. P oc. Na l. Sci. U.S.A. 105, 2008.
[4] Ca ilho E. e al. Unde s anding wax p in ing: a simple mic opa e ning p ocess o pape -
based mic o luidics. Analy ical Chemis y 81(16), 2009.
[5] Sele, C. W. e al. Sel -aligned inkje p in ing wi h sub-hund ed nanome e esolu ion. Ad .
Ma e . 17, 2005.
[6] Si inghaus, H. e al. High- esolu ion ink-je p in ing o all-polyme ansis o ci cui s. Science
290, 2000.
[7] de Gans, B. e al. Inkje p in ing o polyme s: S a e o he a and u u e de elopmen s.
Ad anced Ma e ials, 16(3), 2004.
[8] Yoshioka Y. e al. Simple modi ica ion o shee esis i i y o conduc ing polyme ic anodes ia
combina o ial ink-je p in ing echniques. Mac omolecula Rapid Communica ions, 26(4), 2005.
[9] Se i L. e al. An ampe ome ic glucose biosenso p o o ype ab ica ed by he mal inkje
p in ing. Biosenso s and Bioelec onics, 20(10), 2005.
[10] Se i L. e al. An HRP-based ampe ome ic biosenso ab ica ed by he mal ink-je p in ing.
Senso s and Ac ua o s, 126(1), 2007.
[11] Abe K. e al. Inkje -p in ed pape luidic immuno-chemical sensing de ice. Analy ical and
bioanaly ical chemis y, 398(2), 2010.
35
[12] Abe K. e al. Inkje -P in ed Mic o luidic Mul ianaly e Chemical Sensing Pape . Analy ical
Chemis y, 80(18), 2008.
[13] Fen on E. M. e al. Mul iplex la e al- low es s ips ab ica ed by wo-dimensional shaping.
Applied Ma e ials & In e aces. 1(1), 2009.
[14] B uzewicz D. A. e al. Low-cos p in ing o poly(dime hylsiloxane) ba ie s o de ine
mic ochannels in pape . Analy ical Chemis y, 80(9), 2008.
[15] Ma inez A.W. e al. Diagnos ics o he de eloping wo ld: mic o luidic pape -based
analy ical de ices. Analy ical Chemis y, 82(1), 2010.
[16] Lab on pape . Lab on a Chip, 8, 2008.
[17] Aikio S. e al. Bioac i e Pape s and Fibe P oduc s: Pa en and Li e a u a Su ey. VTT
Wo king Pape s, 51, 2006.
[18] Zimme mann M. e al. Capilla y pumps o au onomous capilla y sys ems. Lab on a Chip,
7(1), 2007.
[19] Ma inez A.W. e al. Pa e ned pape as a pla o m o inexpensi e, low- olume, po able
bioassays. Andgewand e Chemie In e na ional Edi ion, 46(8), 2007.
[20] B uzewicz D.A.e al. Low-cos p in ing o poly(dime hylsiloxane) ba ie s o de ine
mic ochannels in pape . Analy ical Chemis y, 80(9), 2008.
[21] Ma inez A.W. e al. Simple elemedicine o de eloping egions: came a phones and
pape -based mic o luidic de ices o eal ime, o -si e diagnosis. Analy ical Chemis y, 80(10),
2008.
[22] Su S.e al. Mic ogel-based inks o pape -suppo ed biosensing applica ions.
Biomac omolecules, 9(3), 2008.
ANNEX

Annex. Index
I. Pa e n glossa y 2
II. P in e se ings 8
III. Simple symme y 6 (made wi h EPSON and Dima ix) pa e ns using non
pa icle pH based senso eagen . Colou and image da a 10
IV. Simple symme y 6 (made only wi h EPSON) pa e ns using non pa icle
pH based senso eagen . Colou and image da a 13
2
I. Pa e n glossa y
In his sec ion a glossa y wi h all he pa e ns designed o he p ojec has been done. All
pa e ns shapes can be seen obse ed oge he wi h hei espec i e names and impo an
measu es.
In mos cases, pa e n names p o ide use ul in o ma ion abou hem. Fo example, “Simple es ”
pa e n se ies e e o he pa e ns made a he beginning o he p ojec o es ablish some basic
geome y measu es, and “Simple symme y” pa e ns e e o he las pa e ns done, which,
we e e y simple in o de o sol e hei symme y p oblems.
Howe e , mos o he pa e n names p o ide in o ma ion abou hei geome y and measu es.
The s anda d name may be:
C_sX1sX2ci X3wX4chX5 (1)
• sX1 indica es he d opping squa e side leng h
• sX2 indica es he senso squa e side leng h, in case i would be di e en om he
d opping squa e one
• ci X3 indica es he senso zone diame e , in case i s shape would be a ci cum e ence
• wX4 indica es he pa e n wall wid h
• chX5 indica es he channel wid h
I mus be aken in o accoun ha all measu es a e gi en in mm (decimal poin s we e omi ed).
Pa e n names endings p o ide in o ma ion, oo. Fo example, “_sho pa h+” e e s o he
pa e ns whose pa h was made sho e in o de o enhance hei pe o mance. “_sho pa h4”
e e s o pa e ns whose channels a e di ide in o wo.
In he case o “_sho pa h4” pa e ns, hei name may be leng hened in o de o p o ide mo e
use ul in o ma ion. A s anda d name may be:
C_sX1sX2ci X3wX4chX5_c _ch04_X6_sho pa h4 (2)
• _c indica es ha he pa h be ween he d opping squa e and he senso zone has a
ben shape. I i is no he case, _c does no appea
• _ch04_ X6 indica es pa h wid h o he bi u ca ed channels
Fo example, C_s45s4w1ch24_c _ch04_18_sho pa h4 indica es ha he pa e n is composed
by wo squa es, he d opping one has a side o 4.5mm and he senso one o 4 mm. The
channel wid h is 1 mm and he pa h wid h is 2.4 mm. The pa hs a e bi u ca ed in wo, and each
has a wid h o 1.8 mm. The pa h be ween he wo squa es has a ben shape.
O he :
Wall wid h: 0.24 mmSenso squa e: 3.2x3.2 mm
2
Channel wid h: 1.12 mmD opping squa e: 3.2x3.2 mm
2
Name: Simple es 1
O he :
Wall wid h: 0.3 mmSenso squa e: 3.2x3.2 mm
2
Channel wid h: 1.5 mmD opping squa e: 3.2x3.2 mm
2
Name: Simple es 2
O he :
Wall wid h: 0.3 mmSenso squa e: 3x3 mm
2
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: Simple es 3
O he :
Wall wid h: 0.3 mmSenso squa e: 2.5x2.5 mm
2
Channel wid h: 1.5 mmD opping squa e: 2.5x2.5 mm
2
Name: Simple es 4
O he :
Wall wid h: 0.3 mmSenso squa e: 2x2 mm
2
Channel wid h: 1.5 mmD opping squa e: 2x2 mm
2
Name: Simple es 5
O he :
Wall wid h: 0.3 mmSenso squa e: 1.5x1.5 mm
2
Channel wid h: 1.5 mmD opping squa e: 1.5x1.5 mm
2
Name: Simple es 6
O he :
Wall wid h: 0.3 mmSenso squa e: 1.2x1.2 mm
2
Channel wid h: 1.5 mmD opping squa e: 1.2x1.2 mm
2
Name: Simple es 7
O he :
Wall wid h: 0.3 mmSenso a ea: 3 ϕmm
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: C_s3ci 3w03ch15
1
2
3
4
5
6
7
8
3
O he :
Wall wid h: 0.3 mmSenso squa e: 3x3 mm
2
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: C_s3w03ch15
O he :
Wall wid h: 0.3 mmSenso squa e: 3x3 mm
2
Channel wid h: 1.2 mmD opping squa e: 3x3 mm
2
Name: C_s3w03ch12_sho pa h+
O he :
Wall wid h: 0.3 mmSenso squa e: 3x3 mm
2
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: C_s3w03ch15_sho pa h+
O he :
Wall wid h: 0.3 mmSenso squa e: 3x3 mm
2
Channel wid h: 1.8 mmD opping squa e: 3x3 mm
2
Name: C_s3w03ch18_sho pa h+
O he :
Wall wid h: 0.3 mmSenso a ea: 3 ϕmm
Channel wid h: 1.2 mmD opping squa e: 3x3 mm
2
Name: C_s3ci 3w03ch12_sho pa h+
O he :
Wall wid h: 0.3 mmSenso a ea: 3 ϕmm
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: C_s3ci 3w03ch15_sho pa h+
O he :
Wall wid h: 0.3 mmSenso a ea: 3 ϕmm
Channel wid h: 1.8 mmD opping squa e: 3x3 mm
2
Name: C_s3ci 3w03ch18_sho pa h+
O he : bi u ca ed pa hs we e app oxima ely 0.75 mm
Wall wid h: 0.3 mmSenso a ea: 3 ϕmm
Channel wid h: 1.5 mmD opping squa e: 3x3 mm
2
Name: C_s3ci 3w03ch15_sho pa h4
14
15
16
13
12
11
10
9
4
11
pH 9 23 min a e es
Pa e n
L* a* b*
107 65.982
-1.996
-5.785
108 58.820
-2.539
-6.605
109
110
Table AIII1. Colou da a o he Simple symme y 6 pa e ns es ed wi h pH bu e s
III.2. Image da a
Be o e es A e es A e es
Pa e n
pH bu e
used Image Time
(min) Image Time
(min)
Image
93
94 5 7 25
97
98 6 7 20
100
102 7 17
104 20
105 8 5 15
109
110 9 5 14
Table AIII2. Image da a o he Simple symme y 6 pa e ns es ed wi h pH bu e s
Some images o he pa e ns a e shown, oo. As i can be obse ed, some o hem we e
sligh ly a ec ed by co ee ing e ec , al hough his was no a se ious p oblem.
Figu e AIII1. Pa e n 100 (pH 7), Figu e AIII2. Pa e n 101 (pH 7),
17 minu es a e he es 17 minu es a e he es
Figu e AIII3. Pa e n 96 (pH 6), Figu e AIII4. Pa e n 106 (pH 8),
20 minu es a e he es 10 minu es a e he es

12
Figu e AIII5. Pa e n 108 (pH 9), Figu e AIII6. Pa e n 110 (pH 9),
23 minu es a e he es 10 minu es a e he es
13
IV. Simple symme y 6 (made only wi h EPSON) pa e ns using non
pa icle pH based senso eagen . Colou and image da a
IV.1. Colou da a
pH 5 Be o e es 14 min a e es 20 min a e es
Pa e n
L* a* b* L* a* b* L* a* b*
129 77.263
15.742
12.688
68.659
17.605
16.195
70.747
16.594
16.695
130 75.860
17.098
13.828
71.662
18.930
19.402
73.983
16.539
16.664
131 77.292
14.730
12.562
72.374
18.551
18.949
74.369
16.273
18.793
132 77.694
16.379
16.121
74.786
18.227
18.242
75.798
15.523
18.066
pH 5 23 min a e es
Pa e n L* a* b*
129 71.458 15.094 15.621
130 75.602 15.430 14.453
131 75.882 14.910 16.246
132 76.703 14.176 15.945
pH 6 Be o e es 13 min a e es 23 min a e es
Pa e n
L* a* b* L* a* b* L* a* b*
113 77.101
14.383
10.656
76.976
14.910
19.691
76.828
12.867
14.758
114 77.635
14.543
10.629
77.916
13.945
21.977
77.508
11.961
18.922
115 76.655
14.398
10.887
76.036
14.949
21.469
74.495
14.668
18.234
116 77.867
14.742
9.793 77.824
13.664
20.957
76.532
12.227
16.941
pH 7 Be o e es 10 min a e es 16 min a e es
Pa e n
L* a* b* L* a* b* L* a* b*
117 76.544
14.938
11.941
78.906
7.582
25.652
80.490
7.387
21.031
118 76.791
15.004
12.723
81.032
5.008
26.832
82.036
5.176
22.703
119 77.642
14.488
12.672
79.791
5.410
27.227
82.040
4.594
21.492
120 78.665
13.613
12.004
81.492
3.973
24.215
82.196
4.055
22.016
Be o e es 10 min a e es 15 min a e es
133 74.438
15.531
15.848
81.556
6.309
29.762
78.676
7.281
27.527
pH 7 22 min a e es
Pa e n L* a* b*
117 80.378 7.812 18.949
118 82.681 5.090 19.391
119 81.993 5.281 19.438
120 82.904 4.504 19.242
20 min a e es
133 79.355 7.102 24.66
14
pH 8 Be o e es 11 min a e es 16 min a e es
Pa e n
L* a* b* L* a* b* L* a* b*
121 79.237
12.816
11.859
84.149
-1.617
24.250
85.858
-0.273
20.695
122 76.880
14.609
12.652
81.694
1.902
25.527
83.084
2.074
23.445
123 76.159
14.500
12.688
80.609
-2.238
26.672
82.960
-1.121
25.984
124 76.600
15.422
12.277
81.433
-2.871
26.555
84.215
-0.910
24.438
Be o e es 10 min a e es 15 min a e es
134 74.937
15.992
15.418
89.868
-3.223
13.754
87.597
-2.578
15.039
135 76.242
15.754
18.145
88.862
-3.297
21.203
86.011
-3.340
22.941
pH 8 23 min a e es
Pa e n L* a* b*
121 85.890 -0.098 20.059
122 82.835 1.785 23.074
123 84.228 -0.184 22.395
124 85.629 -0.059 21.262
20 min a e es
134 87.700 -2.402 14.789
135 86.220 -2.086 22.160
pH 9 Be o e es 9 min a e es 17 min a e es
Pa e n
L* a* b* L* a* b* L* a* b*
125 76.771
14.367
12.461
73.883
-7.449
0.746
79.451
-4.691
-0.242
126 76.652
14.641
12.660
70.494
-7.320
0.051
75.404
-4.285
-1.270
Be o e es 7 min a e es 13 min a e es
127 74.861
15.852
15.805
77.807
-6.363
2.293
81.416
-5.051
1.613
128 73.892
16.363
16.332
70.582
-7.691
1.242
78.843
-4.656
0.848
136 76.144
16.297
18.031
76.184
-7.047
1.188
81.079
-5.105
0.852
pH 9 24 min a e es
Pa e n L* a* b*
125 78.744 -4.723 -0.949
126 75.053 -4.691 -2.348
20 min a e es
127
128 77.957 -4.426 -0.32
136
Table AIV1. Colou da a o he Simple symme y 6 pa e ns es ed wi h pH bu e s using only
EPSON p in e
15
IV.2. Image da a
Be o e es
A e es A e es A e es
Pa e n
pH bu e
used Image Time
(min) Image Time
(min) Image Time
(min) Image
130
131 5 14 20 23
115
116 6 13 23
117
118 7 10 16 22
122
123 8 11 16 23
125
126 9 9 17 24
Table AIV2. Image da a o he Simple symme y 6 pa e ns es ed wi h pH bu e s
Some images o he pa e ns a e shown, oo. As i can be obse ed, some o hem we e
s ongly a ec ed by co ee ing e ec .
Figu e AIV1. Pa e n 130 (pH 5), Figu e AIV2. Pa e n 131 (pH 5),
20 minu es a e he es 20 minu es a e he es
Figu e AIV3. Pa e n 117 (pH 7), Figu e AIV4. Pa e n 118 (pH 7),
16 minu es a e he es 16 minu es a e he es
16
Figu e AIV5. Pa e n 125 (pH 9), Figu e AIV6. Pa e n 126 (pH 9),
17 minu es a e he es 17 minu es a e he es