Graphene Prints More Smoothly Under The Influence Of Alcohol

August 22, 2020 by Kristina Panos 10 Comments

If you’ve ever sloshed coffee out of your mug and watched the tiny particles scurry to the edges of the puddle, then you’ve witnessed a genuine mystery of fluid mechanics called the coffee ring effect. The same phenomenon happens with spilled wine, and with functional inks like graphene.

Graphene and other 2D crystals print much better under the influence of alcohol.

The coffee ring effect makes it difficult to print graphene and similar materials onto silicon wafers, plastics, and other hard surfaces because of this drying problem. There are already a few commercial options that can be used to combat the coffee ring effect, but they’re all polymers and surfactants that negatively affect the electronic properties of graphene.

Recently, a group of researchers discovered that alcohol is the ideal solution. In the case of spilled graphene, the particles fleeing for the edges are naturally spherical. By adding a mixture of isopropyl and 2-butanol alcohol, they get flattened into a pancake shape, resulting in smoother deformation during the drying process and an easier printing process with better results.

Graphene is quite interesting by nature, and has many uses. It can shift from an insulator to a superconductor with the right temperature changes, and it can desalinate sea water for drinking.

Print Your Way To Keyboard Stability

August 20, 2020 by Kristina Panos 2 Comments

Keyboard key stabilizers, or stabs as they’re known in enthusiast circles, do exactly what you’d expect — they stabilize longer keys like the Shifts and the space bar so that they don’t have to be struck dead-center to actuate evenly. Stabs work by flanking the key switch with two non-functional switch actuators linked with a thick wire bar. Some people love stabs and insist on stabilizing every key that’s bigger than 1u, while other people think stabs are more trouble than they’re worth for various reasons, like rattling.

[Riskable 3D Printing] has been working on a parametric, printable stabilizer system for Cherry MX caps that uses small disk magnets to keep the wire in place. As you can see in the video (embedded after the break), the result is a crisp clacker that doesn’t rattle. The magnets stabilize the wire, so it snaps back quite nicely.

Although the print is an easy one, [Riskable] says the design process wasn’t as cut and dried as it seems. The center points of the stabilizer stems aren’t supposed to be in the center of cutouts, even though it looks that way to the naked eye. After that, the pain point has shifted to the wire, and getting it as straight as possible before making the necessary bends. [Riskable] is going to make a straightener to help out, and we suggest something like this one.

Clacker hacking is quite the rabbit hole, especially when combined with 3D printing. We recently saw a completely 3D-printed macro pad, springs and all.

Continue reading “Print Your Way To Keyboard Stability” →

Printing, Plating, And Baking Makes DIY Microlattices Possible

August 19, 2020 by Dan Maloney 15 Comments

To be honest, we originally considered throwing [Zachary Tong]’s experiments with ultralight metallic microlattices into the “Fail of the Week” bucket. But after watching the video below for a second time, it’s just not fair to call this a fail, so maybe we’ll come up with a new category — “Qualified Success of the Week”, perhaps?

[Zachary]’s foray into the strange world of microlattices began when he happened upon a 2011 paper on the subject in Science. By using a special photocurable resin, the researchers were able to use light shining through a mask with fine holes to create a plastic lattice, which was then plated with nickel using the electroless process, similar to the first half of the electroless nickel immersion gold (ENIG) process used for PCBs. After removing the resin with a concentrated base solution, the resulting microlattice is strong, stiff, and incredibly light.

Lacking access to the advanced materials and methods originally used, [Zachary] did the best he could with what he had. An SLA printer with off-the-shelf resin was used to print the skeleton using the same algorithms used in the original paper. Those actually turned out pretty decent, but rather than electroless plating, he had to go with standard electroplating after a coat of graphite paint. The plated skeletons looked great — until he tried to dissolve the resin. When chemical approaches failed, into the oven went the plated prints. Sadly, it turns out that the polymers in the resin expand when heated, which blew the plating apart. A skeleton in PLA printed on an FDM printer fared little better; when heated to drive out the plastic, it became clear that the tortuous interior of the lattice didn’t plate very well.

From aerogels to graphene, we love these DIY explorations of new and exotic materials, so hats off to [Zachary] for giving it a try in the first place.

Continue reading “Printing, Plating, And Baking Makes DIY Microlattices Possible” →

Model Railroad Engine Gets A Tiny OLED Rollsign While Showing Off Tidy Protoboard Skills

August 19, 2020 by Lewin Day 4 Comments

When catching public transport, it’s very helpful if the bus or train in question has a large display indicating the route or destination. While many transit lines now rely on flipdot or LED displays, the classic rollsign still gets the job done. [diorama111] wanted to emulate this on a model railroad, and set about building a simulacrum at tiny scale.

Intended to suit an HO-scale model train, the build makes use of a tiny 0.6 inch NHD-0.6-6464G OLED display. It’s wired up with a boost converter for power and hooked up to a tiny circuit consisting of an ATMEGA328p and an infrared receiver. The microcontroller is responsible for receiving commands from the remote control, and displaying the appropriate image on the screen. The hidden beauty of this one is well shown in the video below as [diorama111] cleanly and meticulously assembles the circuit on protoboard with just an iron and tweezers.

What makes this project great is how neatly it’s integrated into the body of the train. Nestled inside the locomotive, it almost looks like a stock part of the model. While the nature of the OLED display does come across a touch anachronistic, implementing the vertical scroll really does add a lot to the final effect.

We love to see creative scale modelling projects, and we’ve seen some great work from [diorama111] in the past, too. Video after the break.

Continue reading “Model Railroad Engine Gets A Tiny OLED Rollsign While Showing Off Tidy Protoboard Skills” →

Modified Bricks Can House Energy, Too

August 16, 2020 by Kristina Panos 43 Comments

What if building an emergency battery were as easy as painting conductive plastic onto bricks, stacking them, and charging them up? Researchers at Washington University in St. Louis have done just that — they’ve created supercapacitors by modifying regular old red bricks from various big-box hardware stores.

The bricks are coated in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), a conductive polymer that soaks readily into the bricks’ porous surface. When the coated brick is connected to a power source such as a solar panel, the polymer soaks up ions like a sponge. PEDOT:PSS reacts with the iron oxide in the bricks, the rust that gives them their reddish-orange color. Check out the demonstration after the break — it’s a time lapse that shows three PEDOT-coated bricks powering a white LED for ten minutes.

We envision a future where a brick house could double as a battery backup when the power goes out. The researchers thought of that too, or at least had their eye on the outdoors. They waterproofed the PEDOT-coated bricks in epoxy and found they retain 90% of their capacitance and are still efficient after 10,000 charge-discharge cycles. Since this doesn’t take any special kind of brick, it seems to us that any sufficiently porous material would work as long as iron oxide is also present for the reaction. What do you think?

If you can get your hands on the stuff, PEDOT:PSS has all kinds of uses from paper-thin conductors to homebrew organic LEDs.

Continue reading “Modified Bricks Can House Energy, Too” →

E-Ink Moon Phase Viewer Keeps Interest From Waning

August 16, 2020 by Kristina Panos 6 Comments

It’s a shame that so many cool things happen in the night sky, but we can’t see them because of clouds or light pollution. If you missed seeing the comet NEOWISE or this summer’s Perseid meteor showers, there’s not a lot to be done but look at other people’s pictures. But if it’s the Moon and its phases you keep missing out on, that information can be acquired and visualized fairly easily.

This project includes a bunch of firsts for [Jacob Tarr], like designing a custom PCB and utilizing a three-color E-ink screen to show the Moon in its current phase along with the date and time.

[Jacob]’s moon phase viewer runs on an ItsyBitsy M4 Express, which holds data pulled from NASA ahead of time to save battery. Every morning, the board dishes out the daily info on a schedule kept by a real-time clock module.

We particularly like the minimalist case design, especially the little shelf that holds the lithium-ion cell. This is just the beginning, and [Jacob] plans to add more detail for anyone who wants one for themselves.

If you want something more Moon-shaped, here’s a printed version that gets brighter in time with the real thing. Or you could just make a giant light-up full moon like Hackaday super alumnus [Caleb Kraft].

The Mask Launcher; Like An Airbag For Your Face

August 15, 2020 by Lewin Day 33 Comments

One of the most effective ways to slow the spread of pathogens like the novel coronavirus is to have individuals wear facemasks that cover the nose and mouth. They’re cheap, and highly effective at trapping potentially infectious aerosols that spread disease. Unfortunately, wearing masks has become a contentious issue, with many choosing to go without. [Allen Pan] was frustrated by this, and set out to make a launcher to quite literally shoot masks directly onto faces.

To fire the masks, Allan built a pneumatic system that gets its power from a compact CO2 canister. This is hooked up to a solenoid, which is fired by the trigger. The high-pressure CO2 then goes through a split to four separate barrels cleverly made out of brake line ([Allen] says it’s faster to get parts from the automotive supply than the home store these days). Each barrel fires a bola weight attached to one of the strings of the mask, in much the same way a net launcher works. The mask is then flung towards the face of the target, and the weights wrap around the back of the neck, tangling and ideally sticking together thanks to neodymium magnets.

Amazingly, the mask worked first time, wrapping effectively around a dummy head and covering the nose and mouth. Follow-up shots were less successful, however, but that didn’t deter [Allen] from trying the device on himself at point-blank range. Despite the risk to teeth and flesh, the launcher again fires a successful shot.

While it’s obviously never meant to be used in the real world, the mask launcher was a fun way to experiment with pneumatics and a funny way to start the conversation about effective public health measures. We’ve featured similar projects before, too. Video after the break.

Continue reading “The Mask Launcher; Like An Airbag For Your Face” →