Five colors of Cast21 on five different wrists.

Cast21 Brings Healing Into 2024

September 14, 2024 by Kristina Panos 15 Comments

It takes but an ill-fated second to break a bone, and several long weeks for it to heal in a cast. And even if you have one of those newfangled fiberglass casts, you still can’t get the thing wet, and it’s gonna be itchy under there because your skin can’t breathe. Isn’t it high time for something better?

Enter Cast21, co-founded by Chief Technical Officer [Jason Troutner], who has been in casts more than 50 times due to sports injuries and surgeries. He teamed up with a biomedical design engineer and an electrical engineer to break the norms associated with traditional casts and design a new solution that addresses their drawbacks.

So, how does it work already? The latticework cast is made from a network of silicone tubes that harden once injected with resin and a catalyst mixture. It takes ten seconds to fill the latticework with resin and three minutes for it to cure, and the whole process is much faster than plaster or fiberglass.

This new cast can be used along with electrical stimulation therapy, which can reduce healing time and prevent muscle atrophy.

Cast21 is not only breathable, it’s also waterproof, meaning no more trash bags on your arm to take a shower. The doctor doesn’t even need a saw to remove it, just cut in two places along the seam. It can even be used as a splint afterward.

It’s great to see advancements in simple medical technologies like the cast. And it looks almost as cool as this 3D-printed exoskeleton cast we saw ten years ago.

Thanks to [Keith Olson] for the tip!

Taking Back The Internet With The Tildeverse

September 14, 2024 by Dave Rowntree 21 Comments

For many of us of a particular vintage, the internet blossomed in the ’90s with the invention of the Web and just a few years of development. Back then, we had the convenience of expression on the WWW and the backup of mature services such as IRC for all that other stuff we used to get up to. Some of us still hang out there. Then something happened. Something terrible. Big-commerce took over, and it ballooned into this enormously complex mess with people tracking you every few seconds and constantly trying to bombard you with marketing messages. Enough now. Many people have had enough and have come together to create the Tildeverse, a minimalist community-driven internet experience.

A collaborative Minecraft server hosted on a Tilde site

Tilde, literally ‘ ~ ‘, is your home on the internet. You can work on your ideas on a shared server or run your own. Tilde emphasises the retro aesthetic by being minimal and text-orientated. Those unfamiliar with a command line may start getting uncomfortable, but don’t worry—help is at hand. The number of activities is too many to list, but there are a few projects, such as a collaborative Sci-Fi story, a radio station, and even a private VoIP server. Gamers are catered for as long as you like Minecraft, but we think that’s how it should go.

The Tildeverse also supports Gopher and the new Gemini protocol, giving some people a few more options with which to tinker. The usual method to gain access is to first sign up on a server, then SSH into it; you’re then taken to your little piece of the internet, ready to start your minimalist journey into the Tildeverse.

A couple of videos after the break go into much more detail about the whys and hows of the Tildeverse and are worth a chunk of your time.

We’ve talked about the ‘small web’ before. Here’s our guide to Gemini.

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An Earth-Bound Homage To A Martian Biochemistry Experiment

September 14, 2024 by Dan Maloney 5 Comments

With all the recent attention on Mars and the search for evidence of ancient life there, it’s easy to forget that not only has the Red Planet been under the figurative microscope since the early days of the Space Race, but we went to tremendous effort to send a pair of miniaturized biochemical laboratories there back in 1976. While the results were equivocal, it was still an amazing piece of engineering and spacefaring, one that [Marb] has recreated with this Earth-based version of the famed Viking “Labeled Release” experiment.

The Labeled Release experimental design was based on the fact that many metabolic processes result in the evolution of carbon dioxide gas, which should be detectable by inoculating a soil sample with a nutrient broth laced with radioactive carbon-14. For this homage to the LR experiment, [Marb] eschewed the radioactive tracer, instead looking for a relative increase in the much lower CO₂ concentration here on Earth. The test chamber is an electrical enclosure with a gasketed lid that holds a petri dish and a simple CO₂ sensor module. Glands in the lid allow an analog for Martian regolith — red terrarium sand — and a nutrient broth to be added to the petri dish. Once the chamber was sterilized, or at least sanitized, [Marb] established a baseline CO₂ level with a homebrew data logger and added his sample. Adding the nutrient broth — a solution of trypsinized milk protein, yeast extract, sugar, and salt — gives the bacteria in the “regolith” all the food they need, which increases the CO₂ level in the chamber.

More after the break…

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Create Custom Gridfinity Boxes Using Images Of Tools

September 14, 2024 by Dave Rowntree 3 Comments

We love it when a community grabs hold of an idea and runs wild with it despite obvious practicality issues. Gridfinity by YouTuber [Zach Freedman] is one of those concepts. For the unaware, this is a simple storage system standard, defining boxes to hold your things. These boxes can be stacked and held in place in anything from a desk drawer to hanging off the side of a 3D printer. [Georgs Lazdāns] is one such Gridfinity user who wanted to create tool-specific holders without leaving the sofa. To do so, they made a web application using node.js and OpenCV to extract outlines for tools (or anything else) when photographed on a blank sheet of paper.

The OpenCV stack assumes that the object to be profiled will be placed on a uniformly colored paper with all parts of its outline visible. The first part of the stack uses a bilateral filter to denoise the image whilst keeping edge details.

Next, the image is converted to greyscale, blurred, and run through an adaptive threshold. This converts the image to monochrome, again preserving edge details. Finally, the Canny algorithm pulls out the paper contour. The object outline can be given an accurate scale with the paper contour and paper size specified. The second part of the process works similarly to extract the object outline. The second contour should follow the object pretty accurately. If it doesn’t, it can be manually tweaked in the editor. Once a contour is captured, it can be used to modify a blank Gridfinity base in the model editor.

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Pong In A Petri Dish: Teasing Out How Brains Work

September 14, 2024 by Maya Posch 1 Comment

Experimental setup for the EAP hydrogel free energy principle test. (Credit: Vincent Strong et al., Cell, 2024)

Of the many big, unanswered questions in this Universe, the ones pertaining to the functioning of biological neural networks are probably among the most intriguing. From the lowliest neurally gifted creatures to us brainy mammals, neural networks allow us to learn, to predict and adapt to our environments, and sometimes even stand still and wonder puzzlingly how all of this even works. Such puzzling has led to a number of theories, with a team of researchers recently investigating one such theory, as published in Cell. The focus here was that of Bayesian approaches to brain function, specifically the free energy principle, which postulates that neural networks as inference engines seek to minimize the difference between inputs (i.e. the model of the world as perceived) and its internal model.

This is where Electro Active Polymer (EAP) hydrogel comes into play, as it features free ions that can migrate through the hydrogel in response to inputs. In the experiment, these inputs are related to the ball position in the game of Pong. Much like experiments involving biological neurons, the hydrogel is stimulated via electrodes (in a 2 x 3 grid, matching the 2 by 3 grid of the game world), with other electrodes serving as outputs. The idea is that over time the hydrogel will ‘learn’ to optimize the outputs through ion migration, so that it ‘plays’ the game better, which should be reflected in the scores (i.e. the rally length).

Based on the results some improvement in rally length can be observed, which the researchers present as statistically significant. This would imply that the hydrogel displays active inference and memory. Additional tests with incorrect inputs resulted in a marked decrease in performance. This raises many questions about whether this truly displays emergent memory, and whether this validates the free energy principle as a Bayesian approach to understanding biological neural networks.

To the average Star Trek enthusiast the concept of hydrogels, plasmas, etc. displaying the inklings of intelligent life would probably seem familiar, and for good reason. At this point, we do not have a complete understanding of the operation of the many billions of neurons in our own brains. Doing a bit of prodding and poking at some hydrogel and similar substances in a dish might be just the kind of thing we need to get some fundamental answers.

Soldering, Up Close And Personal

September 14, 2024 by Dan Maloney 13 Comments

A word of warning before watching this very cool video on soldering: it may make you greatly desire what appears to be a very, very expensive microscope. You’ve been warned.

Granted, most people don’t really need to get this up close and personal with their soldering, but as [Robert Feranec] points out, a close look at what’s going on when the solder melts and the flux flows can be a real eye-opener. The video starts with what might be the most esoteric soldering situation — a ball-grid array (BGA) chip. It also happens to be one of the hardest techniques to assess visually, both during reflow and afterward to check the quality of your work. While the microscope [Robert] uses, a Keyence VHX-7000 series digital scope, allows the objective to swivel around and over the subject in multiple axes and keep track of where it is while doing it, it falls short of being the X-ray vision you’d need to see much beyond the outermost rows of balls. But, being able to look in at an angle is a huge benefit, one that allows us a glimpse of the reflow process.

More after the break

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