2026-04-20 23:30:22
You’re probably not going to hang out around Chernobyl any time soon. Still, knowing the conditions there can both satisfy your curiosity and provide scientific value. To that end, [Yury Ilyin] has spent the last couple decades installing homebrew weather stations across the Exclusion Zone for his own interest.
The remote weather stations that [Yury] builds all follow a similar design. Each runs on three 18650 lithium cells, charged via a small solar panel. Most of these cells were salvaged from old laptop battery packs. These cells are used to power a GPRS or WiFi communications module, along with a temperature, humidity, and pressure sensor, and a Geiger counter, because, well… it’s Chernobyl.
He has been lucky enough to keep costs down by finding an old generation GPRS SIM card that could be cloned and used across multiple devices, and thus far has had no trouble receiving signals from his many distributed stations. He’s been able to use his sensor network to track the gradual decline of radioactive emissions in the area from Cs-137, as well as keep an eye on the local weather conditions in an area few ever tread.
[Yury] has built over two dozen of these devices, and several have passed the test of time—with the lithium cells and cellular hardware surviving both high and freezing temperatures as well as the ravages of rain and time. He’s continued to refine the design over the years, starting out with an ATmega644 running the show, and later upgrading to STM32 microcontrollers.
We’ve explored distributed radiation sensor networks before, too, as well as many a remote weather station.
Thanks to [Luc Van Braekel] and [Paulo Ramos] for the tip!
2026-04-20 22:00:59
Rare earth materials are a hot button topic these days. They’re important for everything from electric vehicles to defence hardware, they’re valuable, and everyone wishes they had some to dig up in their backyard. Lithium, too, is a commodity nobody can get enough of, with the demand for high-performance batteries grows each year.
When a material is desirable, and strategically important, we often start thinking of ways to conserve or recycle it because we just can’t get enough. In that vein, researchers have been developing a new technique to recover rare earth metals and lithium from waste streams so that it can be put back to good use.
Enter the technique of flash joule heating. The method is relatively straightforward, in concept at least. It involves a high energy discharge from a capacitor bank, which is passed through a sample of material to be recycled or refined. The idea is that the rapid energy discharge will vaporize some components of the sample, while leaving others intact, allowing the desired material to be separated out and collected in a straightforward and economically-viable manner. It does this in a manner rather contrary to traditional techniques, which often involve large amounts of water, acids, or alkalis, which can be expensive and messy to dispose of or reprocess to boot.
Researchers from Rice have developed this technique to recycle rare earth metals from waste magnets. Imagine all the magnets that get thrown away when things like hard drives and EV motors get trashed, and you can imagine there’s a wealth of rare earth material there just waiting to be recovered.
In this case, the high-energy discharge is applied to waste magnet material in an effort to vaporize the non-rare earth components that are present. The discharge is performed in the presence of chlorine gas, which would chlorinate materials like iron and cobalt in the sample, removing the volatile elements and leaving the rare earth elements behind in solid form. Laboratory experiments were able to refine the material to 90% purity in a single step.
As per the research paper, lifecycle analysis suggested the technique could reduce energy use by 87% compared to contemporary hydrometallurgy recycling techniques, while also reducing greenhouse gas emissions in turn and slashing operating costs by 54%.
The technique can also be applied to separate lithium from spodumene ore. It’s an abundant material, particularly in the United States, and improved ways to process it could increase its value as a source of lithium. When it comes to processing spodumene with flash joule heating, the discharge of electric current makes the lithium in spodumene available to react with chlorine gas. The rapid heating causes the vaporized lithium to form lithium chloride which can be bled off, while other components of spodumene like aluminium and silicon compounds remain behind. It’s basically the opposite of the rare earth recovery method.
As outlined in the research paper, this method achieved recovery of lithium chloride with 97% purity and a recovery rate of 94% in a single step. It’s also a lot simpler than traditional extraction methods that involve long periods of evaporating brine or using acid leeching techniques. Indeed, the laboratory rig was built using an arc welder to achieve the powerful discharge. Other researchers are examining the technique too and achieving similar results, hoping that it can be a cleaner and more efficient method of recovery compared to traditional hydrometallurgy and pyrometallurgy techniques.
These methods remain at the research stage for the time being. Pilot plants, let alone commercial operations, are still a future consideration. Regardless, the early work suggests there is economic gain to be had by developing recycling plants that operate in this manner. Assuming the technique works at scale, if it makes financial sense and recovers useful material, expect it to become a viable part of the recycling industry before long.
2026-04-20 19:00:25
We’ve always been interested in fluidic computers, a technique that uses moving fluids to perform logic operations. Now, Spectrum reports that researchers have developed an electronics-free contact lens that monitors glaucoma and can even help treat it.
The lens is made entirely of polymer and features a microfluidic sensor that can monitor eye pressure in real time. It also has pressure-activated drug reservoirs that dispense medicine when pressure exceeds a fixed threshold. You can see Spectrum’s video on the device below.
This isn’t the first attempt to treat glaucoma, which affects more than 80 million people, with a contact lens. In 2016, Triggerfish took a similar approach, but it used electronic components in the lens, which poses problems for manufacturing and for people wearing them.
Naturally, the device depends on 3D printed molds to create channels and reservoirs in the lens. A special silk sponge in the reservoirs can absorb up to 2,700 times its weight. One sponge holds a red fluid that is forced by pressure into a serpentine microchannel. A phone app uses a neural network to convert the image of the red fluid into a pressure reading.
Two more sponges hold drugs that release at a given pressure determined by the width of the associated microchannel. This allows the possibility of increasing the dose at a higher pressure or even delivering two drugs at different pressure levels.
It is fairly hard to hack your own contact lenses, although we’ve seen it at least once. But smart contacts are not as rare as you might think.
2026-04-20 16:00:35
Nuclear batteries are pretty simple devices that are conceptually rather similar to photovoltaic (PV) solar, just using the radiation from a radioisotope rather than solar radiation. It’s also possible to make your own nuclear battery, with [Double M Innovations] putting together a version that uses standard PV cells combined with small tritium vials as radiation source.
The PV cells are the amorphous type, rated for 2.4 V, which means that they’re not too fussy about the exact wavelength at the cost of some general efficiency. You generally find these on solar-powered calculators for this reason. Meanwhile the tritium vials have an inner coating of phosphor so they glow. With a couple of these vials sandwiched in between two amorphous cells you thus have technically something that you could call a ‘nuclear battery’.
With an approximately 12 year half-life, tritium isn’t amazingly radioactive and thus the glow from the phosphor is also not really visible in daylight. With this DIY battery wrapped up in aluminium foil to cover it up fully, it does appear to generate some current in the nanoamp range, with a single-cell and series voltage of about 0.5 V.
A 170 VAC-rated capacitor is connected to collect some current over time, with just under 3 V measured after a night of charging. In how far the power comes from the phosphor and how much from sources like thermal radiation is hard to say in this setup. However, if you can match up the PV cell’s bandgap a bit more with the radiation source, you should be able to pull at least a few mW from a DIY nuclear battery, as seen with commercial examples.
This isn’t the first time we’ve seen this particular trick. A few years ago, a similar setup was used to power a handheld game, as long as you don’t mind waiting a few months for it to charge.
2026-04-20 13:00:44
We wouldn’t be surprised if you’d never seen the Spira before. The lightweight three-wheel vehicle is closer to a go-kart than a traditional car, and that’s before you even get to the foam body panels. But even the most niche of products enjoys a certain fandom, and [Matt Spears] certainly seems to love working on his Spira. His latest video documents the new modifications he’s made to the car in an effort to ride it on abandoned railroad tracks in the western United States.
His first attempt at riding the rails worked pretty well but he hit an obstruction at high speed which destroyed his front axle and damaged a few other parts on the vehicle, which gave him a perfect excuse to make some upgrades. He swapped the old rear axle out with one from a go-kart, complete with custom wheels and a new braking system. The drivetrain received an upgrade with a 5 kW electric motor, and although [Matt] planned on casting new wheels for the higher speeds, the chemicals he needed didn’t arrive in time. So, to test the new vehicle he repurposed some old wheels just to get the Spria back out on the tracks.
The test run went so well that [Matt] ended up pushing the vehicle farther than he had ever been on this abandoned rail, including over a questionable trestle and far out into the wilderness. Hopefully we’ll see more videos of [Matt] taking this car to explore even more remote places. In the meantime, take a look at some simpler, non-electric vehicles that are often used to explore abandoned rail lines in California.
2026-04-20 10:00:15
Most makers find themselves in need of a benchtop power supply at some point or another. Basic models can be had relatively cheaply, but as your current demands go higher, so does the price. [Danilo Larizza] has figured out an alternative solution—repurposing old server hardware to do the job instead.
The build is based around an HP Common Slot (CS) server power supply. They can be readily had for well under $50 if you know where to look. Even better, they can deliver over 50 amps at 12 volts, which happens to be a very useful voltage indeed. All you need to do is some minor mods.
A jumper on a couple of pins will get the power supply running, and with the addition of some terminals for your hook-up leads, you’re ready to go. As a hot-swappable single unit, the power supply is already outfitted with a ventilation fan to keep everything cool. If so desired, you can even make some further mods to bump output voltage a little ways past 13 or 14 volts if you’d like to use them for certain battery charging tasks.
Sure, you’re not getting a variable power supply, but if you need 12 volts and lots of it, this is a great way to go. We’ve featured similar builds before, too, turning ATX PC power supplies into useful benchtop tools.
