Liquid lens technology has a wide range of applications. Because the liquid lens is so small, light and inexpensive, it can easily be incorporated into a variety of objects. Soon every laptop might come with a built in webcam made from a liquid lens. One of the few disadvantages of a liquid lens made with water is that it is subject to freezing at low temperatures. If you have a cell phone or camera with a liquid lens, be careful not to expose it to very cold temperatures for long periods of time, or you could damage your liquid lens by freezing the water inside it.

2. LENSLENS
A LENS mAy bE dEfiNEd AS A piEcE ofA LENS mAy bE dEfiNEd AS A piEcE of
gLASS, pLAStic or ANy othErgLASS, pLAStic or ANy othEr
trANSpArENt mAtEriAL which iStrANSpArENt mAtEriAL which iS
curvEd oN oNE or both SidES ANdcurvEd oN oNE or both SidES ANd
which mAkES A bEAm of Lightwhich mAkES A bEAm of Light
pASSiNg through it –bENd, SprEAdpASSiNg through it –bENd, SprEAd
out, bEcomE NArrowEr or chANgEout, bEcomE NArrowEr or chANgE
dirEctioN.dirEctioN.

3. ZoomiNg ANd focuSiNgZoomiNg ANd focuSiNg
 ZoomiNg iS A phENomENoN ExhibitEd by AZoomiNg iS A phENomENoN ExhibitEd by A
photogrAphic LENS by virtuE of which AphotogrAphic LENS by virtuE of which A
LENS cAN movE iN from A diStANt to ALENS cAN movE iN from A diStANt to A
cLoSE viEw whiLE kEEpiNg whAt iS bEiNgcLoSE viEw whiLE kEEpiNg whAt iS bEiNg
photogrAphEd iN focuS .photogrAphEd iN focuS .
 it iS Ait iS A mEthod of AdjuStiNgmEthod of AdjuStiNg thE focALthE focAL
LENgth i.E. thE diStANcE bEtwEEN thELENgth i.E. thE diStANcE bEtwEEN thE
middLE of thE LENS ANd thE focuS SuchmiddLE of thE LENS ANd thE focuS Such
thAt thE imAgE bEcomES morE cLEAr.thAt thE imAgE bEcomES morE cLEAr.

5. THE SIMPLEST DEFINITION OF ATHE SIMPLEST DEFINITION OF A
LIQUID LENSLIQUID LENS
wE'vE ALL bEEN driNkiNg A coLd SodAwE'vE ALL bEEN driNkiNg A coLd SodA
whEN thE coNdENSAtioN oN thE SidEwhEN thE coNdENSAtioN oN thE SidE
dripS off. you mAy NoticE thAtdripS off. you mAy NoticE thAt
whAtEvEr iS uNdEr thE wAtEr dropwhAtEvEr iS uNdEr thE wAtEr drop
iS mAgNifiEd. thAt'S A SimpLE vErSioNiS mAgNifiEd. thAt'S A SimpLE vErSioN
of A Liquid LENS.of A Liquid LENS.

6. Liquid LENS thAt iS uSEd iNLiquid LENS thAt iS uSEd iN
vAriouS ELEctroNic dEvicESvAriouS ELEctroNic dEvicES
 A Liquid LENS iS A LENS thAt uSES thEA Liquid LENS iS A LENS thAt uSES thE
propErtiES of two diffErENt LiquidSpropErtiES of two diffErENt LiquidS
withiN A SmALL SpAcE to providEwithiN A SmALL SpAcE to providE
mAgNificAtioN.mAgNificAtioN.
 wAtEr ANd oiL do Not mix, ANd ArE bothwAtEr ANd oiL do Not mix, ANd ArE both
SAfE ANd iNExpENSivE, So thEy ArESAfE ANd iNExpENSivE, So thEy ArE
pErfEct for uSE iN A Liquid LENS.pErfEct for uSE iN A Liquid LENS.
 thE mixturE of wAtEr ANd oiL iSthE mixturE of wAtEr ANd oiL iS
SANdwichEd bEtwEEN two piEcES of cLEArSANdwichEd bEtwEEN two piEcES of cLEAr
gLASS or pLAStic. iN thiS wAy, A Light,gLASS or pLAStic. iN thiS wAy, A Light,
chEAp Liquid LENS iS crEAtEd.chEAp Liquid LENS iS crEAtEd.

7.  bEcAuSE wAtEr AdhErES to gLASS orbEcAuSE wAtEr AdhErES to gLASS or
pLAStic, it NAturALLy formS A bubbLEpLAStic, it NAturALLy formS A bubbLE
ShApEShApE
 thiS bubbLE ShApE withiN thE Liquid LENSthiS bubbLE ShApE withiN thE Liquid LENS
crEAtES mAgNificAtioN ANd vAriAbLEcrEAtES mAgNificAtioN ANd vAriAbLE
focuS.focuS.
 thE oiL compoNENt of thE Liquid LENS fiLLSthE oiL compoNENt of thE Liquid LENS fiLLS
iN thE rESt of thE SpAcE to kEEp thEiN thE rESt of thE SpAcE to kEEp thE
wAtEr from SLoShiNg ArouNd.wAtEr from SLoShiNg ArouNd.

8. ELECTROWETTINGELECTROWETTING
 Water is a polar liquid. Thus its molecules canWater is a polar liquid. Thus its molecules can
be attracted by an electric field. It is thusbe attracted by an electric field. It is thus
possible to change the shape of the liquid drop.possible to change the shape of the liquid drop.
 To carry out this process of electrowetting aTo carry out this process of electrowetting a
water drop is deposited on a substrate made ofwater drop is deposited on a substrate made of
metal, covered by a thin insulating layer. Themetal, covered by a thin insulating layer. The
voltage applied to the substrate modifies thevoltage applied to the substrate modifies the
contact angle of the liquid drop. The liquid lenscontact angle of the liquid drop. The liquid lens
uses two isodensity liquids, one is an insulatoruses two isodensity liquids, one is an insulator
while the other is a conductor. The variation ofwhile the other is a conductor. The variation of
voltage leads to a change of curvature of thevoltage leads to a change of curvature of the
liquid-liquid interface, which in turn leads to aliquid-liquid interface, which in turn leads to a
change of the focal length of the lens.change of the focal length of the lens.

11. DETAILED DESCRIPTIONDETAILED DESCRIPTION
(CONSTRUCTIONAL DETAIL)(CONSTRUCTIONAL DETAIL)
 To start with we take a glass tube which isTo start with we take a glass tube which is
coated withcoated with INDIUM TIN OXIDE (ITO).INDIUM TIN OXIDE (ITO). This isThis is
50nm thin and acts as an electrode.50nm thin and acts as an electrode.
 Then we apply another coating ofThen we apply another coating of
PARYLENE_NITROGENPARYLENE_NITROGEN which acts as anwhich acts as an
insulator between the electrode and water andinsulator between the electrode and water and
this is 3this is 3µm thick.µm thick.
 To force the water volume into a convex shape,To force the water volume into a convex shape,
we apply a top coat of a water-repellingwe apply a top coat of a water-repelling
FLUOROPOLYMER.FLUOROPOLYMER.

12. CONTD…CONTD…
 We fill the tube with an insulator—a mixture ofWe fill the tube with an insulator—a mixture of
PHENYL METHYL SILOXANESPHENYL METHYL SILOXANES that has thethat has the
same density as water in order to make thesame density as water in order to make the
curvature of the interface between the liquidscurvature of the interface between the liquids
perfectly spherical .perfectly spherical .
 When a voltage is applied between the waterWhen a voltage is applied between the water
and the wall electrode, the polar waterand the wall electrode, the polar water
molecules are attracted toward the wall. Themolecules are attracted toward the wall. The
volume of the liquids is constant, so thevolume of the liquids is constant, so the
curvature of their interface will change. If thecurvature of their interface will change. If the
liquids have different refractive indices, theirliquids have different refractive indices, their
interface acts as a variable-focus lens .interface acts as a variable-focus lens .

16. Why WATER?Why WATER?
WATERWATER REDUCES ThE COST OfREDUCES ThE COST Of
mANUfACTURINgmANUfACTURINg DRASTICALLy.DRASTICALLy.
WATER CANNOT bE SCRATChED ANDWATER CANNOT bE SCRATChED AND
ThUS gIvES US AThUS gIvES US A fLAWLESS LENSfLAWLESS LENS..
WATERWATER ISIS mORE TRANSPARENTmORE TRANSPARENT TOTO
LIghT ThAN ANy OThER TRANSPARENTLIghT ThAN ANy OThER TRANSPARENT
mATERIAL.mATERIAL.
WATER IS AWATER IS A POLAR SOLvENTPOLAR SOLvENT AND hENCEAND hENCE
IT IS SUbjECTED TO ELECTROWETTINg.IT IS SUbjECTED TO ELECTROWETTINg.

17. Contd…Contd…
A drop of wAter hAs AA drop of wAter hAs A highhigh
surfAce tensionsurfAce tension And hAs AAnd hAs A
nAturAl curvAture similAr tonAturAl curvAture similAr to
thAt of A conventionAl lens.thAt of A conventionAl lens.
hence the lens obtAined is Ahence the lens obtAined is A
defect free lensdefect free lens..

18. ApplicAtionsApplicAtions
 it hAs got An extensive use init hAs got An extensive use in cellulArcellulAr
phonesphones these dAys. it ActuAlly givesthese dAys. it ActuAlly gives
rise to A smAll system which cAn eAsilyrise to A smAll system which cAn eAsily
be embedded in A smAll device like thAtbe embedded in A smAll device like thAt
of A cellulAr phone.of A cellulAr phone.
 it is used in vArious electronics setsit is used in vArious electronics sets
which integrAte optics with them. forwhich integrAte optics with them. for
e.g.e.g. displAys,cAmerAs,computers.displAys,cAmerAs,computers.

19. contd…contd…
it is used init is used in endoscopeendoscope (in the(in the
field of medicines) which isfield of medicines) which is
developed on A number ofdeveloped on A number of
opticAl functions.opticAl functions.
these dAys it is Also used inthese dAys it is Also used in
tumor detectiontumor detection..

21. AdvAntAgesAdvAntAges
 A liquid lens has got aA liquid lens has got a large focal length rangelarge focal length range..
 One of its most important properties is itsOne of its most important properties is its
ruggedness i.e. it has gotruggedness i.e. it has got no moving parts.no moving parts.
 There is no problem of wear and tear as the lensThere is no problem of wear and tear as the lens
does not have to change position.does not have to change position.
 The time taken by it to respond is very less. ItThe time taken by it to respond is very less. It
has got a speedy response ofhas got a speedy response of 2/1002/100thth
of aof a
second.second.
 It has got a veryIt has got a very good transparencygood transparency in visiblein visible
range.range.

22. contd…contd…
It has got a wide operating temperatureIt has got a wide operating temperature
range i.e.range i.e. -50-50°c°c to 180to 180°c°c ..
TheThe cost of manufacturingcost of manufacturing is veryis very less.less.
It is very compact in size i.e.It is very compact in size i.e. 10µm to10µm to
10mm.10mm.
TheThe curvaturecurvature and the focal length of theand the focal length of the
liquid lensliquid lens can be switched from concavecan be switched from concave
to convex.to convex.

23. contd…contd…
Zoom lens can be created by combiningZoom lens can be created by combining
two liquid lenses.two liquid lenses.
GreatlyGreatly reduces spacereduces space taken up bytaken up by
conventional focus / zoom lens systems.conventional focus / zoom lens systems.
Minimal power usageMinimal power usage . The energy to drive. The energy to drive
the liquid lens is generated by chargingthe liquid lens is generated by charging
the capacitor formed by the wall electrodethe capacitor formed by the wall electrode
and the water. Charging thisand the water. Charging this
approximately 100-pF capacitor requiresapproximately 100-pF capacitor requires
less than a micro joule .less than a micro joule .

25. Physical DimensionsPhysical Dimensions
Diameter of lensDiameter of lens : 10µm-: 10µm-
10mm10mm
 Thickness of lensThickness of lens oror
enclosureenclosure: less than 1mm to: less than 1mm to
2mm.2mm.

26. electricalelectrical
sPecificationssPecifications
Operating voltageOperating voltage
(autofocus)(autofocus): 1.5V: 1.5V
 Power not required inPower not required in
manual focusing mode.manual focusing mode.

27. oPtical sPecificationsoPtical sPecifications
MagnificationMagnification : 10x: 10x
 Focusing latencyFocusing latency : 2 mm –: 2 mm –
infinityinfinity

28. DisaDVantaGesDisaDVantaGes
The only disadvantage of theThe only disadvantage of the
liquid lens is the fact that itliquid lens is the fact that it
should not be subjected toshould not be subjected to
temperature beyond thetemperature beyond the
specified rangespecified range or else wateror else water
will freeze inside it and thiswill freeze inside it and this
may damage our system.may damage our system.

29. ProPoseD remeDiesProPoseD remeDies
The freezing point of the liquidThe freezing point of the liquid
can be improved by addingcan be improved by adding
large quantities of salt (e.g.,large quantities of salt (e.g.,
lithium chloridelithium chloride) or antifreeze) or antifreeze
(e.g.,(e.g., ethylene glycol).ethylene glycol).