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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Building A Multi-Purpose Electrochemistry Device

September 13, 2024 by Dave Rowntree 12 Comments

We don’t get enough electrochemistry hacks on these pages, so here’s [Markus Bindhammer] of YouTube/Marb’s lab fame to give us a fix with their hand-built general-purpose electrochemistry device.

The basic structure is made from plyboard cut to size on a table saw and glued’n’screwed together. The top and front are constructed from an aluminium sheet bent to shape with a hand-bender. A laser-printed front panel finishes the aesthetic nicely, contrasting with the shiny aluminium. The electrode holders are part of off-the-shelf chemistry components, with the electrical contacts hand-made from components usually used for constructing stair handrails. Inside, a 500 RPM 12 V DC geared motor is mounted, driving a couple of small magnets. A PWM motor speed controller provides power. This allows a magnetic stirrer to be added for relevant applications. Power for the electrochemical cell is courtesy of a Zk-5KX buck-boost power supply with a range of 0 – 36 V at up to 5 A with both CV and CC modes. A third electrode holder is also provided as a reference electrode for voltammetry applications. A simple and effective build, we reckon!

Over the years, we’ve seen a few electrochemical hacks, like this DIY electroplating pen, a DIY electrochemical machining rig, and finally, a little something about 3D printing metal electrochemically.

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Using A Potato As Photographic Recording Surface

September 11, 2024 by Maya Posch 11 Comments

Following in the tracks of unconventional science projects, [The Thought Emporium] seeks to answer the question of whether you can use a potato as a photograph recording medium. This is less crazy than it sounds, as ultimately analog photographs (and photograms) is about inducing a light-based change in some kind of medium, which raises the question of whether there is anything about potatoes that is light-sensitive enough to be used for capturing an image, or what we can add to make it suitable.

Unfortunately, a potato by itself cannot record light as it is just starch and salty water, so it needs a bit of help. Here [The Thought Emporium] takes us through the history of black and white photography, starting with a UV-sensitive mixture consisting out of turmeric and rubbing alcohol. After filtration and staining a sheet of paper with it, exposing only part of the paper to strong UV light creates a clear image, which can be intensified using a borax solution. Unfortunately this method fails to work on a potato slice.

The next attempt was to create a cyanotype, which involves covering a surface in a solution of 25 g ferric ammonium oxalate, 10 g of potassium ferricyanide and 100 mL water and exposing it to UV light. This creates the brilliant blue that gave us the term ‘blueprint’. As it turns out, this method works really well on potato slices too, with lots of detail, but the exposure process is very slow.

Speeding up cyanotype production is done by spraying the surface with an ammonium oxalate and oxalic acid solution to modify the pH, exposing the surface to UV, and then spraying it with a 10 g / 100 mL potassium ferricyanide solution, leading to fast exposure and good details.

This is still not as good on paper as an all-time favorite using silver-nitrate, however. These silver prints are the staple of black and white photography, with the silver halide reacting very quickly to light exposure, after which a fixer, like sodium thiosulfate, can make the changes permanent. When using cyanotype or silver-nitrate film like this in a 35 mm camera, it does work quite well too, but of course creates a negative image, that requires inverting, done digitally in the video, to tease out the recorded image.

Here the disappointment for potatoes hit, as using the developer with potatoes was a soggy no-go. Ideally a solution like that used with direct positive paper that uses a silver solution suspended in a gel, but creates a positive image unlike plain silver-nitrate. As for the idea of using the potato itself as the camera, this was also briefly attempted to by using a pinhole in a potato and a light-sensitive recording surface on the other side, but the result did indeed look like a potato was used to create the photograph.

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Boss Byproducts: The Terrible Beauty Of Trinitite

September 4, 2024 by Kristina Panos 17 Comments

While some byproducts recall an idyllic piece of Americana, others remind us that the past is not always so bright and cheerful. Trinitite, created unintentionally during the development of the first atomic bomb, is arguably one of these byproducts.

A see-through vial pendant with several small samples of Trinitite. — A Trinitite pendant. Image via Galactic Stone

Whereas Fordite kept growing back for decades, all Trinitite comes from a single event — the Trinity nuclear bomb test near Alamogordo, New Mexico on July 16, 1945. Also called ‘atomsite’ and ‘Alamogordo glass’, ‘Trinitite’ is the name that stuck.

There wasn’t much interest in the man-made mineral initially, but people began to take notice (and souvenirs) after the war ended. And yes, they made jewelry out of it.

Although there is still Trinitite at the site today, most of it was bulldozed over by the US Atomic Energy Commission in 1953, who weren’t too keen on the public sniffing around.

There was also a law passed that made it illegal to collect samples from the area, although it is still legal to trade Trinitite that was already on the market. As you might expect, Trinitite is rare, but it’s still out there today, and can even be bought from reputable sources such as United Nuclear. Continue reading “Boss Byproducts: The Terrible Beauty Of Trinitite” →

Machining Copper From Algaecide

August 18, 2024 by Al Williams 5 Comments

We love it when we find someone on the Internet who has the exact same problem we do and then solves it. [Hyperspace Pirate] starts a recent video by saying, “Oh no! I need to get rid of the algae in my pond, but I bought too much algaecide. If only there were a way to turn all this excess into CNC machined parts.” OK, we’ll admit that we don’t actually have this problem, but maybe you do?

Algaecide is typically made with copper sulfate. There are several ways to extract the copper, and while it is a little more expensive than buying copper, it is cost-competitive. Electrolysis works, but it takes a lot of power and time. Instead, he puts a more reactive metal in the liquid to generate a different sulfate, and the copper should precipitate out.

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Hydrogen Generation With Seawater, Aluminum, And… Coffee?

August 12, 2024 by Alexander Rowsell 57 Comments

A team at MIT led by [Professor Douglas Hart] has discovered a new, potentially revelatory method for the generation of hydrogen. Using seawater, pure aluminum, and components from coffee grounds, the team was able to generate hydrogen at a not insignificant rate, getting the vast majority of the theoretical yield of hydrogen from the seawater/aluminum mixture. Though the process does use indium and gallium, rare and expensive materials, the process is so far able to recover 90% of the indium-gallium used which can then be recycled into the next batch. Aluminum holds twice as much energy as diesel, and 40x that of Li-Ion batteries. So finding a way to harness that energy could have a huge impact on the amount of fossil fuels burned by humans!

Pure, unoxidized aluminum reacts directly with water to create hydrogen, as well as aluminum oxyhydroxide and aluminum hydroxide. However, any aluminum that has had contact with atmospheric air immediately gets a coating of hard, unreactive aluminum oxide, which does not react in the same way. Another issue is that seawater significantly slows the reaction with pure aluminum. The researchers found that the indium-gallium mix was able to not only allow the reaction to proceed by creating an interface for the water and pure aluminum to react but also coating the aluminum pellets to prevent further oxidization. This worked well, but the resulting reaction was very slow.

Apparently “on a lark” they added coffee grounds. Caffeine had already been known to act as a chelating agent for both aluminum and gallium, and the addition of coffee grounds increased the reaction rate by a huge margin, to the point where it matched the reaction rate of pure aluminum in deionized, pure water. Even with wildly varying concentrations of caffeine, the reaction rate stayed high, and the researchers wanted to find out specifically which part of the caffeine molecule was responsible. It turned out to be imidazole, which is a readily available organic compound. The issue was balancing the amount of caffeine or imidazole added versus the gallium-indium recovery rate — too much caffeine or imidazole would drastically reduce the recoverable amount of gallium-indium.

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Creating 1 Um Features The Hacker Way

August 6, 2024 by Julian Scheffers 9 Comments

[Breaking Taps] has done some lithography experiments in the past, including some test patterns and a rudimentary camera sensor. But now, it’s time to turn it up a notch with 1µm garage semiconductor ambitions.

The e-beam lithography he’s done in the past can achieve some impressive resolutions, but they aren’t very fast; a single beam of electrons needs to scan over the entire exposure area, somewhat like a tiny crayon. That’s not very scalable; he needed a better solution to make 1µm semiconductors.

In his quest, he starts by trying to do maskless photolithography, using a literal projector to shine light on the target area all at once. After hacking a projector devkit apart, replacing blue with ultraviolet and adding custom optics, it’s time for a test. The process works for the most part but can’t produce fine details the way [Breaking Taps] needs. Unfortunately, fixing that would mean tearing the whole set-up apart for the umpteenth time.
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