Printed Brain Implants Give New Meaning To Neuroplasticity

April 14, 2020 by Kristina Panos 4 Comments

3D printing has opened up a world of possibilities in plastic, food, concrete, and other materials. Now, MIT engineers have found a way to add brain implants to the list. This technology has the potential to replace electrodes used for monitoring and implants that stimulate brain tissue in order to ease the effects of epilepsy, Parkinson’s disease, and severe depression.

Existing brain implants are rigid and abrade the grey matter, which creates scar tissue over time. This new material is soft and flexible, so it hugs the wrinkles and curves. It’s a conductive polymer that’s been thickened into a viscous, printable paste.

The team took a conductive liquid polymer (water plus nanofibers of a polystyrene sulfonate) and combined it with a solvent they made for a previous project to form a conductive, printable hydrogel.

In addition to printing out a sheet of micro blinky circuits, they tested out the material by printing a flexible electrode, which they implanted into a mouse. Amazingly, the electrode was able to detect the signal coming from a single neuron. They also printed arrays of electrodes topped with little wells for holding neurons so they can study the neurons’ signals using the electrode net underneath.

This particular medical printing hack is pretty far out of reach for most of us, but not all of them are. Fire up that printer and check out this NIH-approved face shield design.

Using Spiral Mode To Rapidly Print Enclosures

April 13, 2020 by Tom Nardi 24 Comments

We’ve often said that one of the best applications of desktop 3D printing is the production of custom enclosures. A bespoke case adds a touch of professionalism to any project, and considering the materials needed to print one will cost less than even the cheapest generic project box, it’s a no-brainer. There’s only one problem: it can take hours to print even a simple case.

To try and speed things up, [Electrobob] has been experimenting with running off enclosures using spiral or “vase” mode on his 3D printer. Unlike the normal layer-by-layer approach, in this mode, the printer’s hotend continually rises at a steady rate during the entire print. Think of it as akin to printing out a Slinky and you should get the idea.

Spiral printed boxes may need manual retouching

As you might expect, there are some trade-offs here. For one, the walls of the box can’t be very thick since the printer is only making one pass. The nozzle on most printers is 0.4 mm, but in his experiments, [Electrobob] has found he’s able to reliably double that to a wall thickness of 0.8 mm by adjusting the extrusion rate.

You also need to approach the design a bit differently during the CAD phase. Printing holes in the side of the enclosure, which would be easy enough to do normally, doesn’t really work when running in spiral mode. For those situations, [Electrobob] recommends designing a “pocket” into the side that you can come back and cut out with a knife. It will add a little time to the post-processing stage, but the time saved during the print will more than make up for it.

So how much faster are we talking about? In the example [Electrobob] shows in his write-up, the print time went from nearly two hours to just 18 minutes. The resulting enclosure obviously looks a bit different than the traditionally printed version, and isn’t as strong, but the concept still clearly holds promise for some applications. If you’re building a sensor network that needs a bunch of enclosures, those time savings will really add up.

Don’t Let Your PLA Filament Hang Loose With This 3D-Printed Surfboard

April 13, 2020 by Moritz v. Sivers 8 Comments

People always tend to push the boundaries of what is doable with a 3D printer. This is also true for [AndrewW1977] when he decided to 3D print a full-sized functional surfboard.

With just over nine full days of printing time, 95 individual pieces, and using 3.1 kg of PLA (not counting all the test prints), this is certainly a monumental project. One of the bigger issues [AndrewW1977] had to solve was avoiding air pockets inside the board. Ideally, you would want to end up with only one continuous hollow chamber in order to easily vent all the air inside the board when it heats up. [AndrewW1977] chose to overcome this problem by using zero infill for each individual piece. The pieces were then connected with the help of alignment pins that have a central hole thereby connecting all hollow chambers.

By using a triangular shape, he managed to print all pieces without using supports. After gluing them together the whole board was covered with fiberglass and epoxy resin similar to traditional surfboard building. Unfortunately, due to the current situation with Covid19 [AndrewW1977] remains short of showing us the board in action. In case you have a 3D printer at home and lots of spare time during lockdown, [AndrewW1977] has published all files for his surfboard on Thingiverse.

As [AndrewW1977] points out in the video embedded below other people have already done similar projects. From jet boats to electric hydrofoils it seems that water sports and 3D printing are a perfect match.

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Stitching Up Custom Belts

April 12, 2020 by Tom Nardi 17 Comments

If you’ve got a 3D printer, you’re probably familiar with the reinforced belts that are commonly used on the X and Y axis. These belts either come as long lengths that you attach to the machine on either end, or as a pre-sized loop. Traditional wisdom says you can’t just take a long length of belt and make your own custom loops out of it, but [Marcel Varallo] had his doubts about that.

This is a simple tip, but one that could get you out of a bind one day. Through experimentation, [Marcel] has found that you can use a length of so-called GT2 belt and make your own bespoke loop. The trick is, you need to attach the ends with something very strong that won’t hinder the normal operation of the belt. Anything hard or inflexible is right out the window, since the belt would bind up as soon as it had to go around a pulley.

It seems the key is to cut both ends of the belt very flat, making sure the belt pattern matches perfectly. Once they’ve been trimmed and aligned properly, you stitch them together with nylon thread. You want the stitches to be as tight as possible, and the more you do, the stronger the end result will be.

[Marcel] likes to follow this up with a bit of hot glue, being careful to make sure the hardened glue takes the shape of the belt’s teeth. The back side won’t be as important, but a thin layer is still best. The end result is a belt strong enough for most applications in just a few minutes.

Would we build a 3D printer using hand-stitched GT2 belts? Probably not. But during a global pandemic, when shipments of non-essential components are often being delayed, we could certainly see ourselves running some stitched together belts while we wait for the proper replacement to come in. Gotta keep those face shields printing.

Plasma Cutter + Sharpie Is Surprisingly Useful

April 10, 2020 by Al Williams 14 Comments

What we want is a Star Trek-style replicator. What we have are a bunch of different machines that can spew out various 2D and 3D shapes. For the foreseeable future, you’ll still need to post-process most of what you build in some way. [Stuff Made Here] had a challenge. He often uses his plasma cutter to create complex sheet metal items. But the cutter is two dimensional so the piece doesn’t look right until you bend it at just the right places. If you are doing a simple box, it is easy to figure out, but getting just the right spot on a complex bend can be a challenge. His answer? Attach a marker to the gantry so the machine can draw the lines right on the sheet metal.

Sounds easy and if you were willing to do a pen pass separately and then remove the pen and do the plasma cutting it would be relatively easy. However, that seems kind of crude. Mounting it permanently requires a way to raise it up when cutting — and it needs to survive the noisy environment near the torch. The pen would also dry out if you left in uncapped. The answer was using a permanent marker with a click retractor and let the mechanism extend and retract the pen point on command.

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3D Printing Fishing Lure Molds

April 10, 2020 by Al Williams 7 Comments

Every fisherman has a secret. A secret spot, a secret technique, or a secret bait. Maybe that’s why tying flies is so popular. [Steve] certainly has is own special lures, although he’s not keeping it a secret. (Video, embedded below.) He designs lures in Simplify3D, 3D prints molds, and then casts them.

The 3D printing part is interesting, but it is also kind of neat to see the lures and the natural prey he uses for inspiration. If you want to catch fish, you have to use bait that looks like real food.

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The Real Lessons About 3D Printed Face Shields: Effective Engineering Response In Times Of Crisis

April 8, 2020 by Donald Papp 83 Comments

3D printed face shields and other health equipment is big news right now. Not long ago, Prusa Research rapidly designed and manufactured 3D printed face shields and donated them to the Czech Ministry of Health. Their effort is ongoing, and 3D printers cranking out health equipment like the NIH approved design has been peppering headlines ever since.

The Important Part Isn’t 3D Printers

The implied takeaway from all the coverage is that 3D printers are a solution to critical equipment shortages, but the fact that 3D printers are involved isn’t really the important part. We all know printers can make plastic parts, so what should be the real takeaway? The biggest lessons we can learn about Prusa’s ongoing effort are related to how they’ve gone about it.

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