Robo coackroach

Let's Make Our Coackroach

Oh Solar Pocket Factory fans.  How you have played right into our hands.  Oh the irony is delicious!  So ironic.  We made you believe we were trying to change the world with cheap microsolar panels made locally.

Robo Coackroach

HAHAHA.  Who would do that?!

Oh you are so silly.  I now unveil to you the true purpose of our solar experimentation.

MADDIE THE SOLAR MADAGASCAR COCKROACH!  

Robo Coackroach

You may scream now

Step 1: What you need

• A playing card (although a piece of cardstock, cut piece of acrylic, scrap PCB, or really any flat material thinner than 2mm should work), available here
• Double-stick tape:  any will work, but my favorite for all sorts of projects is called Window Tape by Duck
• A couple strips of adhesive copper tape: a must for everyone's solar toolbox.  Readily available at art supply shops or on Ebay
• A piece of acrylic or PET sheet smaller than your playing card: I am using a 70mm x 60mm piece of acrylic.
• Five solettes*, like these from a random Ebay seller
• A pager motor that vibrates when supplied with 0.5VDC- 2VDC, like these
• Clear 5-minute epoxy that is designed to withstand temperatures of at least 90C (or 194F).  I've found the VersaChem 46409 works particularly well
• Hot glue and a hot glue gun
• Teflon sheet (optional)

*If you're new to making photonic robot lifeforms, you might be wondering what a "solette" is.  Solettes are little pieces of mono or polycrystalline photovoltaic silicon, laser cut or hand scribed into smaller pieces for smaller solar panels.  Basically, they are rectangular bits of the magical silicon inside solar panels that transforms light energy into electrical energy.  If that explanation is absolutely unsatisfying to you, your curiosity will be partially relieved by the wise words of Chill Solar Dude

Shameless plug:  I've listed some sources for the above materials, but if you're lazy and/or want to support the future of all that is good and pure, we've got most of the above materials available here too:  http://solarpocketfactory.com/collections/solar-panels

Step 2: Add the copper tape to the playing card

Robo Coackroach

You'll need two pieces of copper tape, to pickup the two poles of the solar panel you are assembling.  Cut, peel, and stick.  Rub it down with the back of your fingernail for that retro gloss finish.

Since we will be making a 2VDC panel (with one solette as a dummy conductor) and this requires 5 solettes, I spaced my copper tape by about 45mm (or 1.75") along the length of the card, with the copper tape coming in at around 25mm wide (or 1").

>>Note that the copper tape conducts best along the surface without the adhesive.  It doesn't conduct reliably through the tape thickness

.

Step 3: Lay down your double-sided tape

Flank your copper tape with some double-sided tape.  Just make sure not to overlap the double-sided tape with the copper tape, since that can cause a reduction in power of your completed solar panel

Step 4: Shingle your solettes with a whistle and a tap

This is the step where the solettes get combined together in series.

In previous Solar Pocket Factory instructables I've shown a couple  techniques involving superglue or conductive paste or soldering.  For the Photonic Madagascar Cockroach you don't need any of that, and you'll be doing something far simpler.  Basically, you need to overlap each solette in a shingling pattern, without any adhesive or solder joints.  Pressure along is what will complete the solar circuit.

This pretty pretty sunset infographic is compliments of a guy who drinks sunshine for breakfast and craps out pure light by dinnertime.

Theory:

Each solette, or any chunk of mono or polycrystalline PV silicon for that matter, outputs around 0.5 - 0.6VDC, which is not enough voltage to do very many useful things.  So, we need to combine enough of these solettes together in series so that their voltage outputs add up.

In order to make the pager motor spin and create the vibration necessary to propel the robot cockroach we need to supply around 2VDC to the motor's input wires.  This means we will need 4 solettes in series (or, 2.0Vopen).  The solettes I recommend using are 13mm x 52mm in size and each will output Im (or, the max current at the maximum power point of the cells - about max power point here: http://en.wikipedia.org/wiki/Maximum_power_point_tracking) of around 150-200 mA per solette, far more than is necessary to make the pager motor spin at full velocity even on a cloudy day.  So, since we are combining the solettes in series, the voltages add up, but the current does not.  Or, to put it another way, 4 of our solettes in series will output 2.0VDC and 150mA-200mA on a nice day and about 1/3 that on a cloudy day

Back to the solettes:  The (+) output is the grey underbelly of the first solette in your shingled stack.  The (-) output of the series connected shingled lineup can be accessed either at the bus bar or white silver ink runners on the blue top surface of the final solette in your stack, or by using a "false" solette that doesn't produce electricity but just serves to bring do the top surface connections to a solette underbelly. This is the easiest and cleanest approach and it's what I show in these photos, and is worth the sacrificial solette in my estimation, just for the simplicity it provides.  So, ignore what I wrote in the paragraph above -- you need 5  solettes if you are using one as a basic conductor.

Practice:

For your first solette, make sure it has part of the white bus bar underneath the solette in contact with the copper tape.  I used a full bus bar solette in this example.  And just overlap the bus bar under the solette with coppertape by at least 2mm to ensure a good stable connection, and the two strips of double-sided tape you laid down will hold it in place.  Blue side up facing the sun.

Now, overlap your second solette by 2mm with the first solette you placed.  Again, at least some of the white conductive bus bar under your second solette needs to be in contact with the white bus bar on the top of your first solette to ensure good conduction.  (this isn't actually strictly true for shingled panels....but more on that in a future instructable).  Repeat this shingling for solettes #3 and #4.  The fifth and last solette you place will need a full bus bar on its underside, to make sure the top of solette #4 gets electrically connected with the copper tape on what will be the (-) side of your panel.  This last solette is really just acting as a conductor, and a piece of aluminum foil or folded copper tape would work as well -- but using this "false" solette gives me the most reliable results and I highly recommend it

Step 5: Encapsulate and cover

To protect your soon-to-be photon-driven
little shop of horrors, a dab of 5-minute 
epoxy with a sheet of acrylic will do the 
job.Epoxy is generally not the best choice 
for making microsolar panels, since it 
yellows in the sun as a result of UV 
degradation.  But,acrylic blocks 
out UV, so this 1-2 combo punch can 
make cheap, long lasting panels.

Or, so the theory goes.  I actually
haven't tested this type of panel for 
more than a few days.  Let me 
know whether this theory matches 
reality or not! 

Just mix up the epoxy -- about 2mL
will do just fine, since it will get 
spread out in the next sub-step.

Blob the epoxy over your solettes.
Add the acrylic topsheet (I used 
1mm thick acrylic, but thinner or 
thick acrylic works fine too).The 
acrylic sheet should just cover your 

solettes with several mm of border,
leaving around 20mm 

of uncovered card on either side,
 as pictured.  I am using 

a 70mm x 60mm piece of acrylic.

And then put 10-20 lbs of mass
on this card-solettes-epoxy-acrylic 
sandwich.  I've been using about 15 lbs 

reliably (which translates to about 2 psi
of pressure on the panel).  Also, you 
should use something non-stick 
separating your compression weight 
from the panel, lest your bug get 
squashed irreversibly forevermore.
I used a sheet of teflon myself.

Let the sandwich cure for about 10 

minutes, then remove theweight 

and voila!  Your panel should now 

put out around 2.5V open and 150mA 

- 200mA Isc in full sunlight.  Even a 

bit less current from the panel will 

work fine for powering up the pager

motor full tilt, since the motors only

 consume tens of mA at 2VDC.

Step 6: Glue the pager motor on the back of your playing card panel

There are a couple main varieties of pager motors out there.  The most popular has an asymmetric mass on the end which causes a vibration of around a few hundred hertz when the mass is rotated.  Another less popular variety is a fully contained disk.  More than you ever wanted to know about pager motors is available here (along with some well spec'd models for high performance Madagascar racing roaches)

          If you're using the asymmetric mass variety, center the mass in the center-ish of the back of your playing card. Add a dab of hot melt glue and then mount the pager motor's body on the hot melt, taking care not to get any hot melt on the rotating mass.  If even a dribble of hot melt gets onto the mass, your roach will likely be bellyside up before you're out of the gate.  So take care at this stage with the glue.

Step 7: Solder the pager motor to the copper back contacts

Copper tape is wonderful to solder onto.  Since kids like to grab real and robotic insects, I used lead-free solder and just got my soldering iron to 350C and the joints are a dream.

I found it generally doesn't matter which wire goes to which piece of copper tape, (+) or (-).  Maybe it does for some motors.  If it does, then just match your red wire on the pager motor to the piece of copper tape under the very first solette you placed, since that will be the (+) of your panel.

Step 8: Fold your legs

This is the last and most crucial step!

Choose which side of the card will be the head of the critter.  Then fold those two corners just like you'd dogear a page in a book.  Those dogears need to be at least 1cm along their sides so that when you card is rest on a surface the spinning pager motor spins free.

Now dog ear the trailing rear of the card.

Theory:

When the pager motor spins, the entire card and panel assembly will vibrate.  The goal of these legs or dogears of the corners of the card is to redirect that vibration in one direction.  Notice in the photo how the front two legs are pointing in the same direction as the trailing legs.  That's key to making your roach a racer rather that a paranoid insect quivering in the corner at prom.

And that's it!

80 watt Foldable Solar Panel

I built this 12v portable, foldable solar panel for $68.00. It's 82 watts, 3.6 amps, and 22v open circuit. It folds into one very nice, very strong and protected carrying case 3/4 thick each piece. Each cell is incased with 10 mil laminate each side (20 mil total) pouches which definately doesn't make this hail proof but it does make each cell strong enough to be handled, mounted and touched with force without breaking.  If i break a cell, i simply cut it out and replace with a new one. These aren't designed to stay outside all the time, however if you add some deck sealant, it's pretty much water proof.

The electrical wire, wood, and hinges, alligator clamps were all purchased from Lowes

The solar cells are purchased from ML Solar LLC "B" Grade

The laminating pouches were purchased off Amazon from Oregan Lamination Co

Tabbing Wire was also purchased off Amazon from Everbright Solar

Copper Slug and Snail Tape purchased off Amazon to make the connection from panel to panel.

Velcro

Make Rad Solar Panels In Minutes With A Sweet Desktop Laminator

Let's Make Rad Solar Panels In Minutes With A Sweet Desktop Laminator

I know what you're thinking.  It's written all over your face.  You're all, "awww, man!  I'm sitting here, ready to make a solar panel, and I've got my silicon cells and EVA all ready and waiting, but my dang kid just threw my soldering iron at the glass I was going to use for the frontsheet, and now the iron and the glass are shattered and on fire, respectively.  How am I ever going to make a solar panel now?  The only other things I've got in the house are a couple transparency sheets and an office laminator.  This mad sucks, yo"
Well, solar friend, don't you worry.  I'm here to tell you about a sweet technique to make water
proof solar panels out of silicon cells with NO soldering, NO glass, and NO money down.  All you need 
a cheapo Staples laminator (got mine for $15 from the Chinese version of Staples down the 
street in Hong Kong, 钉了!), a few simple materials and an iron will

It takes about five minutes to make a small panel, and they're delightfully sturdy, 
waterproof and easy.  Ready?  Once more into that shiny solar breach!(no, not 
that one)p.s.  My boy Chill Solar Dude is coming along on this instructable hayride 
to drop some ill narration on us.  How's it hanging, CSD?

Step 1: A little background on solar

This instructable is all about making solar panels.  Solar panels are different than solar cells--a
solar cell is a single piece of silicon.  Typically, solar cells are low-voltage, high-current devices,
putting out about half a volt, with a current proportional to the cell's area and the intensity of the light.  A modern 6" x 6" cell puts out about 7A of max-power current, at 0.5V*

Electrically, there's not much you can do with 0.5V and 7A.  So we combine solar cells in series and parallel to get to a useful voltage and current.  If we combine ten solettes in series, we get
 five volts at the max power point, which is a generally useful voltage for powering small 
electronics.

The other tricky part about making solar panels is protecting the delicate silicon cells.  These cells are very thin--0.2mm, and they're susceptible to every evil the world has to offer--vibration, humidity, moisture, flexing, heat, cold, bad feelings and hurtful statements.  Once the cells are electrically connected, you have to find some way to wrap them up in a powerful, strong sleeping bag that keeps the warm feelings in and the bad, harmful things on the outside.  This process is called encapsulation.

There's lots of ways to encapsulate solar panels--you can cover them in plastic resin, use huge presses with heaters and vacuums to fix glass and plastic to the front of the panel, and all other kinds of neat tricks to keep the silicon safe and dry.  This instructable is all about a new trick that a friend and I came up with that lets you electrically connect the cells and physically protect them, all using a standard office laminator and a few cents of plastic film.

That's all there is to making solar panels--combine pieces of silicon together, protect them from the harsh outside world, and then ride the solar wave into the glorious sunset.  It's actually quite easy to do.  Read on!

*  If terms like 'max power' and 'short-circuit current' are unfamiliar, check out the other images.  Homey Chill Solar Dude put together some quick tutorials explaining how it all works.

Step 2: Get what you need

There is one very special thing about this method of making solar panels, and that's that it's very cheap and simple.  The cheapest commercial solar panels sell for $.68/W, and homemade solar panels often run higher, because they use very expensive encapsulants.  These panels won't last as long as a glass-laminated panel, but they're made with scrap silicon and some plastic film, making them, to my knowledge, the cheapest, simplest microsolar panels in the world.  The raw material cost for the panels is about $.50/W, a minute to get a good lamination, and you're ready to go!  It's pretty awesome, if I do say so myselfSO, you'll need some materials.  Here's what you need and some places to get it: PET lamination film --  This film 
will make the front and back of your solar panel.
You can get this in your local office supply store 
for laminating papers and ID badges and the like,
or there's plenty of places online that sell PET film 
specifically for solar.  The solar film is UV-stabilized 
and will last longer outdoors.

Shameless plug:  we went ahead and packaged all 

of these materials up in a kit for hacking your own 

solar panels, and you can get it here.  You can get 

the materials other places, too, and I'm listing those 

sources, but we put a lot of effort into sourcing high-

quality materials that work right.  Also, each kit 

comes with ten microliters of Love.

EVA film -- EVA is a rubbery plastic that's very similar to hot glue.  This goes in between the PET film and the solettes, and when heated, forms a perfectly clear, index-matched layer bonding the solettes to the PET.Mechanically, it also cushions the delicate solettes and forms a moisture barrier, waterproofing the panel.  This is a pretty specialized material, so you're unlikely to find a local source, but you can buy big rolls of it on ebay for pretty cheap.

Copper Tape -- this stuff is awesome.  Shiny, real copper with an adhesive backing!  You'll use it to make electrical contact with the enapsulated panel and make a nice connection that you can solder or alligator-clip onto.  You can pick it up at craft stores like Michaels, or there are plenty of cheap sources on ebay.

Doublestick Tape -- you use this to hold the solar cells in place while they're being laminated.  The plastic gets all melty and skooshy, and it tends to push the cells around unless they're taped down.  The best stuff is very thin, very strong tape.  Get it at any stationary store.

Solettes --  This is where the solar magic happens.  These are silicon cells cut to whatever size you want.  The size determines the current of the solar cell--in this instructable, I'm using 52mm x 13mm cells, which put out about 200mA Isc.  You can get these from us or from ebay.  If you do buy from ebay, be sure not to get cells with tabbing--you want just the bare solar cell.

A laminator -- Any desktop laminator will do.  Use one you've got lying around, or pick one up from an office supply store.

A note for the true solar hounddog -- you can get particularly beautiful laminations if you do a simple mod to your laminator to slow it down, so if this project excites you, you might consider dedicating a laminator to the pursuit of solar glory.  I'll go into details of the laminator mods in another instructable.

Step 3: An overview of the underbite

I'm going to make this panel with what we call a "shingled solette" technique.  The solettes are held down to a PET backing using double--stick tape, and they overlap one another slightly, so the negative top of one solette is in electrical contact with the positive bottom of the next solette, making a series connection that adds the solettes' voltages.
What's wonderful about this technique is that you don't have to solder anything.  Just lay the solettes on top of one another, laminate the solettes inside plastic, and the lamination holds the solettes in solid electrical contact.

This video is a good overview of the process--it's a sped-up video of me making a solar panel from start to finish using this technique

Step 4: Step 1: It starts with a backing

The first thing you'll need is a PET backing.  I really recommend using solar PET rather than the lamination sheets--it's a bit thicker and it doesn't get as floppy when you melt it in the laminator.  You can get working panels either way (I used lamination sheets in the video), but the panels come out cleaner with solar PET film.

Decide what voltage panel you want to make.  This will determine how many solettes you have in your panel, and how long your panel will end up.  If your panel is voltage V, you'll have V/2 + 1 solettes, i.e. if you're making a 5V panel, that panel will have 11 solettes.  The shingled solettes should have about 1mm of overlap with their neighbors.

I'm attaching a template for a 5.5V panel that uses 52x13mm solettes.  This makes a ~5.5V, 170mA panel that's good for charging 5V electronics, like phones, cameras, and other devices.  You can print the template directly onto the rough side of the PET backing, which is quite handy.  If you use it, print it out at 1:1 scale on A4 paper.
If you want to make a different size or voltage solar panel, that's fine.  Figure out how many solettes you're using and how large your backing needs to be to accommodate them.  You can as large a margin as you like around your solettes.

Cut your backing out of PET and you're on your way!

Step 5: Step 2: Ze copper tape

The next thing to do is place the copper tape on your backing.  This tape  will bring out the electrical contacts from the panel and let you connect to the panel after it's laminated.

You'll notice the two sides of the PET have different textures--there's a smooth side and a rough side.  The rough side is coated to make it stick better in a lamination.  You're going to place the solettes on that side.

Cut two pieces of copper tape and stick them on either end of the PET. 

 Leave a bit of the tape hanging over the end of the PET piece, and wrap that around to stick on the other side.  Remember, everything on the rough side of the PET is going to be laminated, so you won't be able to get to it.  Wrapping the tape around to the other side lets you access the electrical contacts after the panel is laminated.

Step 6: Step 3--Doublestick

Whichever piece of copper tape you place your first solette on will be the positive contact of your panel.  Choose with care, and you might want to make a mark to remind yourself later (although you'll be able to look at the solettes and figure it out, too)Place the solette so it's centered on the PET and is overlapping the copper tape by several millimeters.  Be delicate with the solettes--they are quite fragile, and it's easy to crack them.  Press the solette down onto the doublestick tape, and thar she goes.

One by one, add the rest of the solettes.  Doublestick tape holds the solettes pretty permanently, so make sure you like how the solette looks before you press it down into the tape.  If you do 
misplacea solette, it's not the 
end of the world.It'll probably 
break, but try to twist it,rather 
than peel it away from the tape.
It it does break, just pull the pieces 
from the tape and put down a fresh 
one.

When you get to the last solette,
take a moment to look at what
it's doing, electrically.  The
bottom of the last solette contacts
both the previous solette and the copper tape.
t's a funny trick that we call the "false solette"
trick--we're just using the conductive bottom
of the solette like a wire to connect the top of the previous solette with the copper tape on the backing.

Once you've finished placing all your solettes, kick back in your chair and take a deep breath.  Relish this moment.  One minute from now, you'll be the proud owner of a finished solar panel, and everything will change.

Step 8: Step 6--sudo make me a sandwich

Now is a good time to preheat your laminator.

First up, make a lamination sandwich.  Take a piece of EVA and lay it on top of the solettes, and then take another piece of PET and lay it, rough side-down, on top of the EVA.  Your baby is ready for the hot rollers!

  The doublestick tape should keep everything in place, but all the same, be gentle with the unlaminated panel.  Pick it up and feed one end into the laminator.  It's important to laminate the panel along the length of the panel--feeding it in a different way may crack your solettes.  Chill Solar Dude made a drawing for you, for clarification.

The laminator will pick it up and start pulling it through.  On the other side of the laminator, you'll see a beautiful panel emerge like a dhota from an air chrysalis.

You may notice that my laminator looks like the terminator 

while he's being lowered down into the pool of molten steel.  Yours doesn't have to look like that.  I've been tinkering with my laminator so frequently that I've wised up and stopped putting the cover back on, but you just do this with a normal, off-the-shelf laminator, and it'll work just fine.

Most desktop laminators run too cold and fast to fully melt a panel.  The easiest way to handle this is to pass your panel through the laminator several times, and each time, it'll melt a little more.  This is a dirt-simple method, and it makes panels that work fine, but it leaves small bubbles inside a panel where the EVA didn't fully melt.

The best way I've found to make good-looking panels is to slow it down by stopping the laminator every ~10mm or so and waiting a few seconds for the panel to melt, then advancing it another 10mm.  This lets the panel spend more time under the hot rollers, melting the plastic more thoroughly, and then the laminator's rollers can completely squeeze out any bubbles in the plastic, giving a perfectly clear, smooth panel.

When you're feeding the panel into the laminator, you might get your plastic layers slightly misaligned.  That's fine.  Once your panel is laminated, you can trim down any sloppy edges with scissors and get a nice clean edge.

Well there you go.  Ain't nothing left to do but test 'er out

Step 9: Well? Did it work?

 I made a nine-solette panel.  One of those solettes

 is a false solette and doesn't add voltage to the 

panel, but each of the other solettes adds half a volt

 at the max power point, so I should see 4 volts at 

the max power point.

I plugged it into our little solar testbed, and lo and 

behold, the panel's putting out 208mA at 3.7V at 

the max power point, or .75W.  Pretty good, ain't 

that right, Chill Solar Dude?

Step 10: Wellsir, I reckon it's time to hit the ol' dusty trail

Well, that's about it I reckon.  Go forth and build cool stuff.  Show everybody what you make in the comments!

If you think this is neat, well, my amigo Shawn and I do this all the time, and we're busy making lovely tiny little machines that make solar panels