Here’s a photovoltaic cell that can be printed onto paper. The manufacturing technique is almost as simple as using an inkjet printer. The secret is in the ink itself. It takes five layers deposited on the paper in a vacuum chamber. But that’s a heck of a lot easier than current solar cell fabrication practices. In fact, is sounds like the printing process is very similar to how potato chip bags are made. This is significant, because it could mean a fast track to mass production for the technology.

It isn’t just the easy printing process that excites us. Check out the video after the break where a test cell is placed on top of a light source while being monitored by a multimeter. It’s been folded like a fan and you can see a researcher sinch up the cell into a small form for storage. It’s a little counter-intuitive; for instance, you wouldn’t want to make a window shade out of it because it would have to be down during the day to get power. Be we think there’s got to be some great use for these foldable properties.

[Thanks Rob]

Grab some stiff paper and get to work building your own paper claw. [Dombeef] posted the instructions to recreate the claw above because he was unsatisfied with his previous design which was flimsy and unable to pick up just about anything. This version is a bit larger and it internalizes all of the parts.

Being paper craft, you don’t need much in the way of materials or tools. A push-pin makes holes for the paperclip and wire which serve as the pivot points. Glue and some tape hold the rest of assembly together. You can see a video of the final product after the break. A shaft at the center closes the claw when pulled, and opens it when pushed to opposite way. This makes it perfect for that home-made crane game (or was that a claw game?)… as long as you’re not trying to pick up anything too heavy.

Why spend time etching circuit boards and applying solder masks when all you really need is a rollerball pen and some paper? That’s what University of Illinois professors [Jennifer Lewis and Jennifer Bernhard] were asking when they set off to research the possibility of putting conductive ink into a standard rollerball pen.

The product of their research is a silver nanoparticle-based ink that remains liquid while inside a pen, but dries on contact once it is applied to a porous surface such as paper. Once dry, the ink can be used to conduct electricity just like a copper trace on a circuit board, making on the fly circuit building a breeze.

Previous ink-based circuit construction was typically done using inkjet printers or airbrushing, so removing the extra hardware from the process is a huge step forward. The team even has some news for those people that think the writable ink won’t hold up in the long run. The ink is surprisingly quite resilient to physical manipulation, and they found that it took folding the paper substrate several thousand times before their ink pathways started to fail.

While we know this is no substitute for a nicely etched board, it would be pretty cool to prototype a simple circuit just by drawing out the connections on a piece of paper – we can’t wait to see this come to market.

This circuit illustration adds a scrolling paper feeder to the bed of a laser cutter. In the video after the break you can see that the actual assembly is put on the bed of the laser cutter. After the laser has cut out the specified pattern, the scroll is wound to move an un-cut portion into place. It uses a servo motor to drive one of the spools.

An Arduino Uno with a servo shield is being used for this application. It has one button which winds one spool for a pre-programmed period of time. There’s a few issues with this setup, namely that it’s not tied into the CNC program that runs the laser. There’s also a lack of precision when using a continuously rotating servo like this. If it were upgraded to use a stepper motor and patched into the CNC hardware this would make cutting new scrolls for your player piano a breeze.

Here’s a project that does the opposite, it takes old player piano rolls and digitizes them.

Here in the Midwest it sometimes seems like Spring will never, well…spring. We get that “April showers bring May flowers”, but nearly all of the last month has been cold and rainy around these parts. While things are improving, we think it’s always good practice to have a few fun projects at the ready, just in case your plans with the kids get rained out.

We think that Hackaday reader [Dombeef’s] papercraft strandbeest is a perfect idea for a rainy afternoon. The supply list is pretty short, requiring little more than some scissors, pliers, paperclips, and glue in addition to the thick paper that makes up the body of the strandbeest. The paper is cut into pieces according to the PDF template he includes in his Instructable, secured to one another via small pieces of paperclip.

Once the legs are all constructed, a main axis is built from one of the remaining paperclips, and everything is joined together under the main portion of the strandbeest’s body.

As you can see in the video, the legs work quite well, though the strandbeest can probably benefit from a hand crank in the short term. [Dombeef] plans on adding a small motor to his creation, which should get the strandbeest moving about quite rapidly once completed.

If you are looking for more fun projects to do with the kids, look no further than this papercraft gyroscope or these squishy circuits.

Although spring keeps trying to break through the winter doldrums you might be looking for just one more weekend activity before the outdoor season begins. Grab the kids and give this paper gyroscope a try.

It’s not an electronic sensor made of paper, but the modern equivalent of a spinning top. The frame remains stationary while the center assembly spins at high speed, keeping the whole thing balanced on one narrow point. [Dombeef] put together a printable template which you can use to make your own parts. He got a hold of the heavy paper that’s used to hold X-ray film, but you can just trace out multiple copies of the parts and make a beefy section by laminating them together with glue. Combine the inner and outer parts using a paper clip as the axis and you’re ready to go. Pull hard on a bit of floss wound around the axis to get the center frame spinning, then sit back and see how long it will remain standing.

Part PCB, part old IC, and held together with hot glue. It doesn’t take much to make this electronics stand, but it’ll certainly add to the geek level of your desk.

Decorate with light

This busy living room is actually decorated all in white. The patterns that give it life are on lend from a projector and what we’d imagine is some fantastic software. [Thanks MDV]

Flashing butt on your bike

[Eli] sewed lights and flex sensor into her jeans. Now her butt flashes in heart-shaped patterns as she rides. She actually robbed one of the flex sensors from this project to complete that explosive high-five project.

Mini-rake’s progress

A lathe and some sand that needs tending is all that [Spatula Tzar] needed to get this zen garden rake under way. We like how she used a vacuum bag to infuse the wood with mineral oil.

Paper and electrons

This collection of musical projects forsakes common substrates and builds the mess of circuit boards on pieces of paper. Not much information but the strangeness is worth a look.

Cheap paper accelerometers? Put us down for a dozen to start. They’re not quite ready for mass production yet but it looks like they’re on the way.

[George Whitesides] led a team to develop the new technology that uses simple manufacturing methods to produce the sensor seen above. Graphite and silver inks were screen printed onto heavy paper. The single limb sticking out from the body of the sensor is a separate piece of paper that bends the carbon area when force is applied. This changes the carbon’s resistance which is measured using a Wheatstone bridge constructed by gluing resistors to the device.

It sounds unsophisticated compared to most of the accelerometer modules we’re used to, but if you need a sensor that detects sudden motion this sounds like the perfect part. Now who wants to be the first person to replicate this in their basement?

[Thanks Fabien]

[Sivan Toledo] needed a enclosure for a unique sized electronic project, not finding what he needed in off the shelf solutions, he went to the next best thing, … Papier Mâché!

Using a mold made out of standard corrugated cardboard, he slowly built up layers made of magazine paper, and ordinary “white glue” diluted with water. After getting near the thickness wanted he switched over to typing / copy type paper for a nice clean outer surface. Ports were made in the usual fashion when dealing with soft or thin material, drill a smaller hole, going back with successively larger holes, and then follow up with an appropriate file, all while taking things slow along the way to prevent unwanted results. Finishing up with layers of paper carefully cut into strips to meet the circumferences / edges, along with the final outer surface to make it all even.

The end result is awesome as it stands, but we cant help but wonder what some sanding and paint would look like on a enclosure made like this, though any way you finish it, the idea comes down to custom enclosures that do not need special tools or materials to complete (on the cheap).

Thanks [Drone]

Take a few minutes out of your day, grab your scissors, and learn how a simple processor works. [Saito Yutaka] put together an exercise to teach processor operations with paper. After downloading the PDF you can cut out the Address and Data pointer as well as two-bit data tokens for each. The processor has three instruction sets; Increment register by one, Jump if not over flow, and Halt wait for reset.

Once you’ve got your cutouts you can follow along as the program is executed. The INC operation is run, with the JNO used to loop the program. Once the register has reached an overflow the overflow counter halts the program.

One word of warning, we think there’s a typo in one of the captions.  Once the program starts running and gets to address 01(2) the caption still reads 00(2) for both address and data. As long as you compare the values in the picture along the way you should have no problem getting through execution. which has now been fixed.

[Manuel] built his own thermal printer based around an Arduino. We’re a bit confused about the parts, his webpage specifies an EFA-1019HW2 print head but the bill of materials on his github shows EPT-1019W2. We can’t find a source for either product number, but we did find similar thermal line printers for as low as $32.00. The controller boards on the other hand look to be around $150 so building your own is a definite win. [Manuel's] version can print 96 points and has a font set that prints 32 characters per line. Check out the video after the break and let us know if the noise of the print head is a deal killer for you.

This on-wrist navigation system uses Google Maps and something called… paper. This is a throwback to scroll-based directions from the 1920′s and 30′s that [Simon] built. He soldered a couple of brass tubes to a brass back plate, then added sides and a face crystal. Now he prints out step by step direction from the popular mapping website and winds them onto scrolls. We’re not sure that we’d take the time to do this, but hey, at least the screen resolution is fantastic and you don’t have to worry about battery life.

Who would have thought that some corn starch could be made into toner transfer paper? We’re not sure of the advantages (perhaps its cheaper?), but if you have a lot of time or just love to get sticky [Matthew Sager] shows the proper method for making the paper, printing, and then etching a PCB.

If you’re just getting started making PCBs, we recommend you check out these DIY circuit etching videos to get a better grasp on the printing and etching steps.

For those unaware, the little acronym above stands for Do-It-Yourself-Direct-To-Garment printing. In layman’s terms, printing your own shirts and designs. Commercial DTGs can cost anywhere from $5,000 to $10,000 which for the hobbyist who only wants a few shirts is ridiculous. So you would think this field of technology would be hacked to no end, but we’ve actually only seen one other fully finished and working DIYDTG. So we took it upon ourselves to build a DIYDTG as cheaply and as successfully as possible.

We would like to take this moment to thank [makemygraphix] for his original designs, as ours is heavily based off his. And Tshirt Forums, for their valuable input.

For your own DIYDTG you’ll need a few parts, (we honestly just used what we had lying around)
-3/4 inch particle board/plywood/MDF
-1/2 inch particle board/plywood/MDF
-1/4 inch plywood
-1 and 1/2inch wood screws
-24inch ball bearing drawer track
-scrap aluminum (1/16″ thick)
-Epson printer (more on this below)

The printer you choose is the most absolutely crucial part of this hack. We took apart an HP DeskJet 3845, Canon iP1500, Brother MFC420CN, Epson Stylus Photo 820 and an Epson Stylus c40. Why so many? We literally purchased every printer the local thrift store had (at $6 a printer, it’s not that bad actually), that way the reader wouldn’t have to. Our findings were thus; the HP and the Canon both had rotary encoders on the paper feed shaft and ended up being a total peta to try to align and get working, both not recommended. The Brother was an all-in-one that would not function unless every part was connected, making it too large and bulky for our needs. Both Epsons used stepper motors, were very easy to take apart, and only had one easy to manage paper sensor. Go with Epson! (We ended up using the C40 because it had the 3 ink CYM system instead of the 5 CYMLCLM system the 820 did).

As for the ink you will be using in your printer, we found DTGinks.com to be a good resource.

For software for your Epson, we found the default drivers worked well enough. There is RIP software out there, but we couldn’t find any that supported the c40. We will recommend the SSC Utility program though. Allowing you to quickly and easily lie to the printer about how much, what kind, and replaced ink cartridges (for Epson only).

For tools we recommend the following
-measuring tape
-square
-pen/chalk line
-table saw
-circular saw
-jigsaw
-Dremel
-drill press/drill (and an assortment of bits)
-sand paper/file

We started off by taking apart the printers. Every printer is different, so we can’t give you details but its relatively simple process. By the end you’ll only need the head and its carriage, the paper feed motor and its shaft, and the power supply.

You’ll need to cut the wood as follows, (it should be noted, these are slightly different then what we actually used)
For the 3/4 inch,
1 x 26inch by 11 and 1/2 inches.
1 x 26inch by 10 inches.

For the 1/2 inch,
2 x 26inch by 5inch,
2 x 26 inch by 1 and 3/4 inches.

First clamp the two 26″x5″ boards together. Now 6″ from the end and 2″ and 3/8″ from the bottom drill a 5/8″ hole through both boards at the same time. This is where your paper feed shaft will go.

Here is a tricky part, the metal track. We mounted the outer part 3/4″ from the top on one of the 26″x5″(doesn’t matter which you choose) pieces and made the stop/back/end of the track flush with the end of the board (this isn’t very high priority) . And the inner part of the track goes 1″ and 1/8″ from the top on one of the 26″x1 and 3/4″ pieces.

Normally we do recommend that you use metal “L” brackets to attach corners of wood, but as long as you pre-drill a hole slightly smaller than your screws, you’ll be fine (we also counter sunk most of our screws, but that’s optional). Attach the two 26″x1 and 3/4″ to the  26″x10″. Do the same with the two 26″x5″ and the 26″x11 and 1/2″ pieces.

All that was a little tricky, so here is a picture to help out. For those wondering, the top tray rolls “towards” you in this image.

And a shot without the top tray, as you can see our shaft wasn’t long enough, so a simple 2″x3″ piece was put in place. Make sure the shaft spins freely and without binding, with and without the top tray in.

The next interesting part is mounting the drive motor. It needs to be snug against the gear of the shaft, yet not too tight to make it grind against the wood. It also needs to have a way of preventing the shaft from “popping out”. We solved both problems relatively simply.

Take your assembly, remove the top shelf, and prop it on its side. Position your motor where it will be mounted on top/inside the 26″x5″ piece. Drop in the shaft, get everything aligned and draw a circle around the motors base. Using a straight edge and tangent lines you can approximate the center of your circle.

Use a large hole saw cut it out (it doesn’t have to be perfect). Sand/file it so the motor easily fits in without bending any pins. We pop riveted a 1″x3″ piece of aluminum to the motor to make mounting a little easier.

Drop in your shaft and make sure everything lines up. Finally, to prevent the shaft from slipping in, we used the washers and C clamp from the extra printer parts (you didn’t throw away, right?) on the other 26″x5″ piece. And to avoid the shaft from slipping out we took a 1″x10″ piece of aluminum, bent it in a “_n_” shape, drilled a hole for the shaft, and used a cut up spring from the extra printer parts. A picture is worth 1000 words,

Bare with me, we’re almost done!

You’ll need to modify the printer carriage now, simply cut off the slot that paper used to come through,

You’ll want to mount it on-top of the two 26″x5″ pieces about 6″ back. We were lucky and found two of the previous mounting screw holes on the carriage fit perfectly, however other printers you might need to bend or make your own. (This picture taken before we made our nifty “_n_” bracket).

Now we made our platen, this is the thing your shirt goes on. It’s really up to you how its made, and we’re not even totally happy with our design, so play around and find what works best. Ours is 24″x9 and 1/2″ piece of 1/4″ plywood mounted to the top of two 20″x2 and 7/8″ pieces of 1/2″ plywood. The height measurement completely depends on the height of your head. For those wondering, we never got an answer for how far the shirt should actually be from the head, but we’ve found about 1/8″ works well enough. (The “legs” you see on our platen were later taken off.)

Mount your power supply and solder it, alongside your motor, to the driver board.

Now there is one part we’ve neglected to mention until now. And that is the paper feed sensor (remember that one sensor we mentioned earlier?). Well it’s because we spent 3 days trying to get that sucker to work with our platen. We tried everything, different timings and positions of the platen, even programming an MCU to try to trick the printer into thinking the platen was paper. In the end, we just broke it off.

By accident.

And it worked (no really!) It takes a little timing on our part but by hand to trigger the sensor, but we’ve never had a misprint like we did with the platen. (Pictured below, one of our “tape” attempts at triggering the paper feed sensor, this one worked about 1 out of 50 times).

Powered on,

Send a print job, hand trigger the paper feed sensor, and we have a print!

Here is just a short video if it in action, most notably you can see us hand triggering the paper feed sensor. The orange was a test print, as you can see if your platen isn’t 100% flat and level relative to the head, you’ll get some smudging and general print errors. The white shirt was a perfect (well, test) print that we did a little earlier.

(Yes, we know the video was blocked earlier. We have re-uploaded it, thank you for your patience; it should work now.)

*Disclaimer, using tools without proper ear and eye protection can result in a visit to the hospital. And HaD is in no way responsible for any damages. Be smart, be safe.*

[Steve Hoefer] pulled together a great hack for the friendless. This glove will play a heated game of rock-paper-scissors against you. [Steve] realized that the middle and fourth fingers are all that need to be monitored to decide which of the three signs you are making. He used flex sensors on the back of these fingers as an input. There is also an accelerometer to judge the three shakes that lead up to the shoot.

The small screen you see displays what the glove chose and is a hack in itself. This idea adapts from an Evil Mad Scientist project, using three sheets of acrylic etched with the different icons and edge-lit with LEDs. All of this, along with a speaker and scoreboard, connect to an Arduino. The icing on the cake? [Steve] coded an adaptive learning algorithm that observes your playing style to gain an advantage.

See this in action after the break. Once you’ve mastered rock-paper-scissors you should consider building other glove-based peripherals.

[Thanks Zokier]