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.

Here’s a step-by-step guide for printing etch resist directly to copper clad boards. Two methods of making printed circuit boards at home have long dominated as the favorites; using photo-resist, and the toner-transfer method. The latter involves printing board artwork on a laser printer and then ironing it onto the copper clad. We’ve seen some efforts to print toner directly to the copper, or to use ink to adhere toner and then heat fuse it, but this hack is the first one we remember seeing that uses an inkjet printer directly.

The best reason inkjet printing isn’t often used is do to the ink’s iability to protect copper from the etchant. This method uses MISPRO ink that is pigment based and will resist the acid. An Epson Stylus Photo R260 printer was chosen because you can get refillable printer cartridges which work with the ink, and they’re fairly easy to modify. In order to feed substrate through the device it needs some physical alteration to make room for the thickness of the material, and an ATtiny13 has been added to trick one of the sensors.

Unfortunately we didn’t find photos of the printed resist. But there is source code available for the tiny13 if you do give this a try.

[Thanks Pavlejo]

This is an inkjet print head made using a RepRap. The manufacturing process is both simple and ingenious. It uses a vibrating piezo buzzer to pump printing liquid through a tiny nozzle. The red disc seen above is exactly the same diameter as the piezo that resides behind it. There is a hole offset from the center to feed ink in between the two discs. Take a look at the test footage after the break.

To make the nozzle a hole was cut in the plastic disc, then a pin inserted and the whole thing was covered with hot glue. The next step was to remove the pin and shave down the glue until the narrow aperture is open. [Adrian Bowyer] is still in the testing phase for this assembly, but once he gets the bugs worked out he plans to test it with a heating element so that it can print using wax and other materials that are liquid when hot.

[Vik] tipped us off about this one after seeing the printable transistors from the other day.

[Jeri Ellsworth] continues her experiments with electroluminescence, this time she’s making EL ink. The ink she’s looking for is Zinc Sulfate in a solution. The process she chose is to re-dope some glow powder so that it can be excited by the field around an AC current. In her video (embedded after the break) she talks about the chemical properties she’s after by detailing a cubic lattice of zinc and sulfur atoms with an added copper atom (adding that atom is a process called doping).

The quick and dirty synopsis of the experiment starts by washing the glow powder with dish soap to acquire zinc sulfide crystals. Then she combined copper sulfate and zinc shavings from the inside of a modern penny to yield copper metal and zinc sulfate suspended in solution. That was mixed with the zinc sulfide from the glow powder washing and doped with a little more copper sulfate. The excess liquid is poured off, the test tube is capped with glass frit, and the whole thing hits the kiln to start the reaction. The result glows when excited by alternating current, but could have been improved by adding chlorine atoms into the mix.

We’re excited every time we see one of [Jeri's] new chemistry hacks. We’d love to see more so if you’ve come across interesting chemistry experiments during your Internet travels, please let us know about them. Just make sure you have some idea of what you’re doing when working with chemicals… safety first.

The txtBomber is a high-tech graffiti printer developed by [Felix Vorreiter]. Details are a bit scarce but the video clip after the break proves that this works quite well. [Felix] admits this is Arduino powered but we’re going to have to guess at the rest of the setup from the pictures. He says there are built-in-pens so we’d bet there’s a felt-tip type of thing going on and those look like seven solenoids that actuate them. He posted a picture of the handle side of the device and we can make out two wheels that are connected to LEGO gears. This tracks movement of the txtBomber across a surface in order to synchronize the printing process. There’s no sign of an LCD so it looks like you have to pre-program the messages before you go out into the field.

This is akin to the Chalkbot, but the messages that leaves wash away with the rain. This one seems like it might get you into some trouble if you get caught leaving permanent tags around the neighborhood.

[Thanks Kermit M]

The number one and number two things asked after presentation of our DIYDTG were…
“How does it hold up in the wash?”
and…
“How did you change out the inks?”
While we’ve explained the first several times (regular ink washes out, DTG ink gets a little lighter but survives) we can hopefully answer the second with a tutorial.

To change out or refill the Epson cartridges we used was relatively simple. You’ll need a few supplies.
-Old/used (or new, but you would be wasting ink) Epson cartridge
-DTG ink (we recommend DTGinks.com)
-SSC utility (this lets your trick the printer into thinking it has a fresh cartridge)
-Windex (ammonia base won’t rust the print head)
-Plastic syringe
-Flat head screw driver
-Hot glue
-Electrical tape
-Small cup
-Rags (ink gets everywhere)
-Resolve or other stain remover (to clean up said ink everywhere)
-Time (a lot of it)
-(Optional) sponge from other printers
-(Optional) latex gloves
-Original head waste collection piece from printer.

The bottom item on the list is a small funnel and squeegee that were originally located just below the head when it is at ‘home’ position within your printer. Its job was to suck ink out of the head, cleaning it and priming it at the same time.

Fair warning, your fingers will be black/stained without gloves.

You’ll want to first take the flat head screwdriver and crack open the cartridge’s top. Make sure it stays intact, we will be reusing it and glueing it back on. From there, pull out the old sponge that resides in the cartridge.

Pour some Windex in a cup and place in the cartridge and top. You can either soak the original sponge as well in the cup, or cut a new sponge. We don’t recommend kitchen sponges (too many large holes), but we found several clean sponges in old printer’s ‘ink recycle receptacle’ – for lack of a better term.

Let it soak (we recommend overnight).

I’ll take this moment to explain how to prime your head. You’ll want to make sure you put in some cartridge: ink, DTG ink, Windex, or other. Just don’t try to prime your head with air/no cartridge!

Take your syringe, and push it onto the hose that is connected to the waste collection piece.

You’ll position it below the head’s nozzles (seen in the picture below as dots), push it against the head with one hand. Using your other hand, pull out the syringe (creating a vacuum). You should get a nice thick stream of whatever cartridge you put in. If not, wiggle around the waste collection piece until a seal is formed. We pull out on average about 1ml of liquid to prime.

(Optional) If you think your printer has a lot of clogged heads, you can take out the cartridge from the cup. Place it in your printer head, and fill it with Windex. Prime as explained above. Your heads should be clean and clear.

Once your sponge has soaked (or you cut a new one), simply drop ink/DTG ink onto the end of the sponge that will be pushed into the cartridge first. We used about 10ml, do NOT fill your sponge completely.

Stuff the soaked end first into the cartridge, pushing it down to the bottom, but make sure you don’t push too far, the top of the sponge has to touch the lid (why that’s important in a moment).

You’ll notice that by squashing down the sponge into the cartridge, the extra previously unfilled area of the sponge gets soaked.

Push on your lid, and hot glue around the edge, it must be air tight (but not so much so you can’t ever get the lid off again, we assume you’ll want to refill again). And place a small amount in any holes except the main center one.

By having the lid done this way (with the sponge and glue) you’re creating an air tight seal that only lets out the correct amount of ink. If you cleaned out your head before with Windex (that optional stage), with no sponge and no lid as instructed, you may have noticed just how easily without this seal that fluid will just fall out of the head, you don’t want that.

(Pictured below, ink dribbling out)

Wrap a tight piece of electrical tape over the cartridge, covering and sealing the bottom hole completely. Only once around is needed, too many and the plastic spike may not be able to pierce the tape.

Place the cartridge into the head, from here on out, until the cartridge is completely empty, do NOT remove it from the head. Prime your head. At this point if you put too much ink into the sponge you’ll see it fall out of the head (as mentioned above). Don’t worry, just leave it. Place a rag underneath and wait (once again, overnight is prefered). By morning you should be able to wipe away all the excess, prime it, and no ink will ‘just fall out’.

We also added a small piece of rag to act as a squeegee to help clean the head when it returned to home position.

You’re done! Do a lot of test printing, you’ll find that some of the first prints will be messy (it took us 10 full prints before we got it to be constant darkness).

We’ll ask it again, why aren’t we building our own printers? We’re building 3d printers, CNC mills, and hacking the ink cartridges on commercial printers. What does it really take to build say a 300 dpi black and white printer? Something that lets you clean and service the print head rather than throwing it out when the ink reservoir is empty?

Someone has set out to answer these question with the Openprinter project. If this interests you, join up and start the revolution. RepRap had simple beginnings and maybe it’s time to take the army of self-replicating 3D printers and use them to print parts for 2D printers that don’t drive us crazy.

[Photo credit]

[via LostScrews]

Xerox has announced a breakthrough in printable circuits. They’ve developed a conductive ink called “silver bullet” that can be printed on many different types of substrate to create circuits. The key part of the new ink is its lower melting point. Plastic film substrate melts at 150 degrees Celsius but the ink is liquid when ten degrees cooler to avoid damaging the film. This begs the question: how do you then solder components to the circuit?

The benefits of printable circuitry are obvious. Aside from cheaper and easier RFID, disposable circuits like greeting cards, and fabric-based electronics, we’re hoping this will facilitate more environmentally friendly PCB fabrication. That really depends on the ink’s production process and the resilience of the resulting circuitry.

[via Gizmodo]

This ancient by internet standards, circa 2002, but its a great read.  [Eddie], frustrated by the high cost of ink cartridges set out to build a continuous inking system. This would mean that the cartridges would be filled from larger, cheaper reservoirs of ink continually. Along the way he transitioned from simple tubes with some putty to more complicated systems. Eventually he had to hack the chips that told the printers the cartridge was in need of replacement.  While the systems he’s using may be difficult to find now, the execution should work on other models. Completely unrelated to the project itself, is that [Billy Mays] as the site favicon? We suspect it is [Eddie] himself.

[via hacknmod]

[Jen Hui Liao] created a device that guides the user into drawing a portrait of themselves. Dubbed Self-Portrait Machine, it comments on how much in society is created by machines and we are dependent on them. Unlike previous drawing robots, the user is part of the sketching process. The machine holds the users hands and uses stepper motors and servos to move them around like a LOGO turtle. Liao promises to have more details available soon. Video of the machine after the jump.