Experimenting with a liquid lens and driver IC--- make money online

so it's continuously variable in its

focal length across a pretty wide range

hey everyone this is an older project

that I did two or three years ago but

thought I would dust it off because I've

got a new application for it

this is a liquid lens driver and this is

a liquid lens here so what's a liquid

lens it's this is a an optical device

that can change focal length based on

the electrical signal that we give it

and it has no real moving parts it's

built by putting a drop of water sort of

into an oil liquid and when you apply

power to the lens the polar is the water

molecules are polarized whereas the oil

molecules are not so when you apply an

electric field to the lens the water

molecules are pulled preferentially more

than the oil molecules and it will

change the shape of the droplet of water

so if the oil and water have different

indices of refraction that you get a

lens effect so changing the shape of the

meniscus in there will change the power

of the lens this is actually not really

new technology the biggest company that

makes these lenses is called very optic

so a couple years ago I got in contact

with very optic and wanted to get some

lenses and they said oh yeah sure we got

a development kit that costs like

$10,000 which is incredibly stupid

charging potential developers ten grand

anyway so I started looking for products

that had liquid lenses in them so that I

could cannibalize the products and this

is one of them

this digitus USB webcam and even more

annoyingly this is not available or at

least it wasn't available two or three

years ago in the US so I had to have

these shipped in from Germany very

expensive stupid process to get one of

these lenses very optic is really I hope

they've gotten better about getting

their their products into the hands of

developers but anyway this is what the

camera looks like so there's the lens so

I cracked one of these open and the lens

looks like a little button

and I just sandwiched it between these

two copper clad boards to make

electrical

tact with it so inside here one of these

copper clad boards is one electrode and

the others is the other electrode so to

drive one of these lenses you need a

fair amount of voltage the lens is

connected directly to this chip which is

a specialized liquid lens driver chip

it's an H v89

- made by super Tex this was also a

difficult chip to get and it's difficult

to solder package it's surface mount and

I couldn't find any standard breakout

boards for this particular layout so I

actually had to have this breakout board

made just just to get the pins

accessible the nice thing is that the

chip doesn't require very many external

components just three capacitors is it

one downside is that the chip only works

with I squared C you can't really just

give it an analog voltage or send it to

a serial or parallel data signal it has

to be I squared C so I'm using an

Arduino just to send it the I squared C

data as someone wrote a an I squared C

library called wire for Arduino which is

why I'm using it and I didn't really

feel like learning about I squared C for

this okay so let me set this thing up

and use it so you can see what it looks

like okay so there you can see that the

the lens is changing focal length I've

got the camera lens fixed so it won't

try to autofocus on us and I'm dialing

it in and out with the potentiometer

that's on this control box here so it's

pretty neat to be able to change the

lenses focal length it has quite a large

range - off to get the spec but it

really goes quite far it's it's it's

able to focus at many different focal

lengths and that ear optical quality is

you know not bad so if I move closer to

the camera eventually it should go out

of focus again and then I'll be able to

compensate and see getting a little dark

here you can see it's still sharp we're

losing a light because the lens is

relatively small in diameter pretty neat

and if I turn the potentiometer all the

way down my program just cycles through

all the different all of the available

focal

automatically so I was thinking of

building my own liquid lens that would

be quite large like maybe three inches

in diameter made even bigger like a

ship's portal I think it would be really

cool to have a window that could change

focal length you know maybe not just

quite through as large of a range as

that little lens but at least to make it

interesting the problem is the two

fluids are quite specialized they have

to have the same density so that when

you turn the lens vertically or

horizontally the meniscus doesn't change

shape that one has to be polar one has

to be nonpolar and they have to have

different indices of refraction so that

you actually get a good lensing effect

and having all these properties is

actually pretty difficult I mean the

densities really have to be the same

they have to be tuned mixed so that they

come out just right so I'm looking into

that and they have to be immiscible of

course to obviously think mix together

that would ruin the whole thing

so I'm looking into that and you also

need very high voltages to drive a

bigger lens to because the the pole

exerted on the liquid interface you know

goes down with the square of distance so

you need a lot more voltage to make a

bigger lens work as far as I know this

is actually uses a principle called

electrowetting which may not require

quite as much voltage but I'll put some

links in the description there you could

also run one of these lenses off just

plain old AC voltage you don't really

need this specialized chip for it the

reason that the voltage should be AC is

so that the lens fluids don't become

polarized so if you made one electrode

positive all the time and the other

electrode negative the fluid itself can

charge up and the lens would kind of

drift over time so instead if you flip

the polarity of the thing it won't

change the optical properties because

the electric field would be the same and

the pole exerted on the fluid would be

the same but you won't have polarization

effects so this thing this chip tops out

at about 60 volts for this size lens and

obviously you could just get a 60 volt

AC source and run it that way - okay

hope this was helpful see you next time

byeTop Paid Keyword :  earn cash online, google make money from home, earn money online without investment by clicking ads, free earn money website, online money making jobs, earn money online without investment by typing, online work for money, best online earning sites, make money online with google, online earning websites, money making websites, online earning websites for students,