Polymer Discovery Gives 3D-printed Sand Super Strength

November 21, 2021 by Dave Rowntree 29 Comments

Research activity into 3D printing never seems to end, with an almost constant stream of new techniques and improvements upon old ones hitting the news practically daily. This time, the focus is on a technique we’ve not covered so much, namely binder jetting additive manufacturing (BJAM for short, catchy huh?) Specifically the team from Oak Ridge National Laboratory, who have been exploring the use of so-called hyperbranched Polyethyleneimine (PEI) as a binder for jetting onto plain old foundry silica sand (nature, free access.)

The PEI binder was mixed with a 75:25 mix of water and 1-propanol (not to be mixed up with 2-propanol aka isopropanol) to get the correct viscosity for jetting with a piezoelectric print head and the correct surface tension to allow adequate powder bed penetration, giving optimal binding efficiency. The team reported a two-fold increase in strength over previous jetting techniques, however, the real news is what they did next; by infusing the printed part (known as the green part) with common old ethyl cyanoacrylate (ECA, or super glue to us) the structural strength of the print increased a further eight times due to the reaction between the binder and the ECA infiltrate.

To further bestow the virtues of the PEI binder/ECA mix, it turns out to be water-soluble, at least for a couple of days, so can be used to make complex form washout tooling — internal supports that can be washed away. After a few days, the curing process is complete, resulting in a structure that is reportedly stronger than concrete. Reinforce this with carbon fiber, and boy do you have a tough building material!

Not bad for some pretty common materials and a simple printing process.

We covered a similar binder jetting process for using sawdust a little while ago, and a neat way of printing with metal powder by carrying it in a stream of argon and cooking it with a laser, but there is an opening for a DIY effort to get in on the binder jetting game.

Thanks [Victor] for the tip!

Friday: Getting Social With Discord And Bring-a-Hack

November 17, 2021 by Tom Nardi 14 Comments

With just a few days to go before the kickoff of the 2021 Hackaday Remoticon, we’re still working furiously behind the scenes to pack as much content as possible into the two day virtual event. In fact, there’s so much going on that we thought you’d appreciate getting a bit of a head start as far as planning your own personal course through the weekend goes. The event might be free, but that’s no reason not to squeeze as much out of it as you can.

Chat It Up on Discord

To begin with, you’re really going to want to join the official Hackaday Remoticon Discord server. We know some subset of the Hackaday readership would rather we used Matrix, or IRC, or maybe carefully modulated smoke signals; but at the end of the day, Discord has bubbled to the top as the defacto choice for this kind of thing. Give it a shot, you might actually like it.

The Discord server isn’t just a place for like-minded hackers to hang out and discuss the musical stylings of DJ Jackalope during the Saturday afterparty. It’s also how attendees can ask questions at the end of each presenter’s talk, as we’ll be turning off YouTube chat to keep things centralized. Even if you don’t plan on communicating with others (though you really should), the Discord server has an interactive schedule of events which will let you sign up to be notified when the talks you’ve selected are about to start, and we’ll be dropping important announcements and links in there as the event goes on.

Friday Bring-a-Hack on Gather Town

Friday night ends with a Bring-a-Hack where attendees can show off whatever they’ve been working on using Gather. It’s a video chat platform inside a virtual 2D world that looks a bit like Legend of Zelda.

Using this virtual environment, you can easily drop into an ongoing video stream simply by walking up to the presenter. Once you’ve seen enough, just walk over to the next little cluster of users. The point is to recreate the experience of stopping by a crowded after party where everyone brought some hardware project along with them to get spark conversations. Space will be limited, with ticket holders and people in Discord getting the first dibs, so keep an eye on your inbox for information about how to join.

Of course this is not the only Friday evening activity. A few weeks ago we announced that Lewin Day will be hosting Hacker Trivia, giving our beloved commenters the chance to show off your unimpeachable knowledge of technology and Hackaday history. The Friday talk stream will dump immediately into trivia, but here’s the dedicated link if you want to set a reminder for yourself.

Try It, You’ll Like It!

It’s difficult, perhaps even impossible, to truly recreate the experience of going to an in-person hacker con. But with interactive events and the latest and greatest communication software, we’re hoping the 2021 Remoticon can get pretty close. All the pieces are in place, the only thing we need now is to have a whole bunch of excited hackers to join in and have a good time. Think you can help us out?

This Week In Security: The Battle Against Ransomware, Unicode, Discourse, And Shrootless

November 5, 2021 by Jonathan Bennett 20 Comments

We talk about ransomware gangs quite a bit, but there’s another shadowy, loose collection of actors in that arena. Emsisoft sheds a bit of light on the network of researchers and law enforcement that are working behind the scenes to frustrate ransomware campaigns.

Darkside is an interesting case study. This is the group that made worldwide headlines by hitting the Colonial Pipeline, shutting it down for six days. What you might not realize is that the Darkside ransomware software had a weakness in its encryption algorithms, from mid December 2020 through January 12, 2021. Interestingly, Bitdefender released a decryptor on January 11. I haven’t found confirmation, but the timing seems to indicate that the release of the decryptor triggered Darkside to look for and fix the flaw in their encryption. (Alternatively, it’s possible that it was released in response the fix, and time zones are skewing the dates.)

Emsisoft is very careful not to tip their hand when they’ve found a vulnerability in a ransomware. Instead, they have a network of law enforcement and security professionals that they share information with. This came in handy again when the Darkside group was spun back up, under the name BlackMatter.

Not long after the campaign was started again, a similar vulnerability was reintroduced in the encryption code. The ransomware’s hidden site, used for negotiating payment for decryption, seems to have had a vulnerability that Emsisoft was able to use to keep track of victims. Since they had a working decryptor, they were able to reach out directly, and provide victims with decryption tools.

This changed when the link to BlackMatter’s portal leaked on Twitter. It seems like many people hold ransomware gangs in less-than-high regard, and took the opportunity to inform BlackMatter of this fact, using that portal. In response, BlackMatter took down that portal site, cutting off Emsisoft’s line of information. Since then, the encryption vulnerability has been fixed, Emisoft can’t listen in on BlackMatter anymore, and they released the story to encourage BlackMatter victims to contact them. They also suggest that ransomware victims always contact law enforcement to report the incident, as there may be a decryptor that isn’t public yet. Continue reading “This Week In Security: The Battle Against Ransomware, Unicode, Discourse, And Shrootless” →

Hackaday Podcast 132: Laser Disco Ball, Moore’s Law In Your Garage, Cheap Cyborg Glasses, And A Mouse That Detects Elephants

August 20, 2021 by Mike Szczys 3 Comments

Hackaday editors Elliot Williams and Mike Szczys debate the great mysteries of the hacking universe. On tap this week is news that Sam Zeloof has refined his home lab chip fabrication process and it’s incredible! We see a clever seismometer built from plastic pipe, a laser, and a computer mouse. There’s a 3D printed fabric that turns into a hard shell using the same principles as jamming grippers. And we love the idea of high-powered lasers being able to safely direct lighting to where you want it.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 132: Laser Disco Ball, Moore’s Law In Your Garage, Cheap Cyborg Glasses, And A Mouse That Detects Elephants” →

Discount Microfluidics From A $9 Spree At The Dollar Store

July 11, 2021 by Al Williams 1 Comment

Microfluidics — working with tiny volumes of fluids in tiny channels — isn’t something you’d think would be inexpensive. Unless you read [Alexander Bissells’] post on how he created microfluidic devices using stuff from the dollar store. The channels in these devices can be much smaller than a millimeter and the fluid volumes are sometimes measured in femtoliters. At those scales, fluids don’t work like we intuitively think they will.

The parts list included gel tape, baby droppers, and some assorted containers and tools. Total price at the dollar store $9. One of the key finds in the dollar store was some small spray bottles. They weren’t important themselves, but they contain small lengths of silicone tubing and that was useful. Plastic fresnel lenses along with the tubing and gel tape worked to make “chips.” The gel tape also gets cut to make the channels. An eyedropper with some modifications makes a reasonable syringe.

We aren’t sure what you can practically do with any of these, but the T-junction looked pretty interesting. If you want some ideas on how these devices work in biology, including COVID-19 testing, check out this article. And just last week [Krishna Sanka] hosted a Hack Chat on microfluidics in biohacking, you can find the transcript on the project page. If you need a pump, this one uses 3D printer firmware to control it.

Lego Microscope Aims To Discover Future Scientists

June 28, 2021 by Dan Maloney 7 Comments

When it comes to inspiring a lifelong appreciation of science, few experiences are as powerful as that first glimpse of the world swimming in a drop of pond water as seen through a decent microscope. But sadly, access to a microscope is hardly universal, denying that life-changing view of the world to far too many people.

There have been plenty of attempts to fix this problem before, but we’re intrigued to see Legos used to build a usable microscope, primarily for STEM outreach. It’s the subject of a scholarly paper (preprint) by [Bart E. Vos], [Emil Betz Blesa], and [Timo Betz]. The build almost exclusively uses Lego parts — pretty common ones at that — and there’s a complete list of the parts needed, which can either be sourced from online suppliers, who will kit up the parts for you, or by digging through the old Lego bin. Even the illuminator is a stock part, although you’ll likely want to replace the orange LED buried within with a white one. The only major non-Lego parts are the lenses, which can either be sourced online or, for the high-power objective, pulled from an old iPhone camera. The really slick part is the build instructions (PDF), which are formatted exactly like the manual from any Lego kit, making the build process easily accessible to anyone who has built Lego before.

As for results, they’re really not bad. Images of typical samples, like salt crystal, red onion cells, and water fleas are remarkably clear and detailed. It might no be a lab-grade Lego microscope, but it looks like it’s more than up to its intended use.

Thanks for the heads up on this, [Jef].

Retrotechtacular: Discovering Aerodynamics With The Chrysler Airflow

June 16, 2021 by Dan Maloney 31 Comments

When you think about it, for most of human history we’ve been a pretty slow bunch. At any time before about 150 years ago, if you were moving faster than a horse can run, you were probably falling to your death. And so the need to take aerodynamics into consideration is a pretty new thing.

The relative novelty of aerodynamic design struck us pretty hard when we stumbled across this mid-1930s film about getting better performance from cars. It was produced for the Chrysler Sales Corporation and featured the innovative design of the 1934 Chrysler Airflow. The film’s narration makes it clear why the carmaker would go through the trouble of completely rethinking how cars are made; despite doubling average engine horsepower over the preceding decade, cars had added only about 15% to their top speed. And while to our 21st-century eyes, the Chrysler Airflow might look like a bulked-up Volkswagen Beetle, compared to the standard automotive designs of the day, it was a huge aerodynamic leap forward. This makes sense with what else was going on in the technology world at the time — air travel — the innovations of which, such as wind tunnel testing of models, were spilling over into other areas of design. There’s also the influence of [Orville Wright], who was called in to consult on the Airflow design.

While the Airflow wasn’t exactly a huge hit with the motoring public — not that many were built, and very few remain today; [Jay Leno] is one of the few owners, because of course he is — it set standards that would influence automotive designs for the next 80 years. It’s fascinating too that something seemingly as simple as moving the engine forward and streamlining the body a bit took so long to hit upon, and yet yielded so much bang for the buck.

Continue reading “Retrotechtacular: Discovering Aerodynamics With The Chrysler Airflow” →