E-Waste And Waste Oil Combine To Make Silver

September 14, 2025 by Tyler August 12 Comments

As the saying goes, “if it can’t be grown, it has to be mined”– but what about all the metals that have already been wrested from the bosom of the Earth? Once used, they can be recycled– or as this paper charmingly puts it, become ore for “urban mining” techniques. The technique under discussion in the Chemical Engineering Journal is one that extracts metallic silver from e-waste using fatty acids and hydrogen peroxide.

This “graphical abstract” gives the rough idea.

Right now, recycling makes up about 17% of the global silver supply. As rich sources of ore dry up, and the world moves to more sustainable footing, that number can only go up. Recycling e-waste already happens, of course, but in messy, dangerous processes that are generally banned in the developed world. (Like open burning, of plastic, gross.)

This paper describes a “green” process that even the most fervant granola-munching NIMBY wouldn’t mind have in their neighborhood: hot fatty acids (AKA oil) are used as an organic solvent to dissolve metals from PCB and wire. The paper mentions sourcing the solvent from waste sunflower, safflower or canola oil. As you might imagine, most metals, silver included, are not terribly soluble in sunflower oil, but a little refining and the addition of 30% hydrogen peroxide changes that equation.

More than just Ag is picked up in this process, but the oils do select for silver over other metals. The paper presents a way to then selectively precipitate out the silver as silver oleate using ethanol and flourescent light. The oleate compound can then be easily washed and burnt to produce pure silver.

The authors of the paper take the time to demonstrate the process on a silver-plated keyboard connector, so there is proof of concept on real e-waste. Selecting for silver means leaving behind gold, however, so we’re not sure how the economics of this method will stack up.

Of course, when Hackaday talks about recycling e-waste, it’s usually more on the “reuse” part of “reduce, reuse, recycle”. After all, one man’s e-waste is another man’s parts bin–or priceless historical artifact.

Thanks to [Brian] for the tip.Your tips can be easily recycled into Hackaday posts through an environmentally-friendly process via our tipsline.

A worker inspects JUNO's acrylic sphere under the watching eye of PMTs

Worlds Largest Neutrino Detector Is Collecting Data In China

September 1, 2025 by Tyler August 16 Comments

To say that neutrinos aren’t the easiest particles to study would be a bit of an understatement. Outside of dark matter, there’s not much in particle physics that is as slippery as the elusive “ghost particles” that are endlessly streaming through you and everything you own. That’s why its exciting news that JUNO is now taking data as the world’s largest detector.

First, in case you’re not a physics geek, let’s go back to basics. Neutrinos are neutral particles (the name was coined by Fermi as “little neutral one”) with very, very little mass and a propensity for slipping in between the more-common particles that make up everyday matter. The fact that neutrinos have mass is kind of weird, in that it’s not part of the Standard Model of Particle Physics. Since the Standard Model gets just about everything else right (except for dark matter) down to quite a few decimal points, well… that’s a very interesting kind of weird, hence the worldwide race to unravel the mysteries of the so-called “ghost particle”. We have an explainer article here for anyone who wants more background.

Continue reading “Worlds Largest Neutrino Detector Is Collecting Data In China” →

Google Will Require Developer Verification Even For Sideloading

August 26, 2025 by Maya Posch 115 Comments

Do you like writing software for Android, perhaps even sideload the occasional APK onto your Android device? In that case some big changes are heading your way, with Google announcing that they will soon require developer verification for all applications installed on certified Android devices – meaning basically every mainstream device. Those of us who have distributed Android apps via the Google app store will have noticed this change already, with developer verification in the form of sending in a scan of your government ID now mandatory, along with providing your contact information.

What this latest change thus effectively seems to imply is that workarounds like sideloading or using alternative app stores, like F-Droid, will no longer suffice to escape these verification demands. According to the Google blog post, these changes will be trialed starting in October of 2025, with developer verification becoming ‘available’ to all developers in March of 2026, followed by Google-blessed Android devices in Brazil, Indonesia, Thailand and Singapore becoming the first to require this verification starting in September of 2026.

Google expects that this system will be rolled out globally starting in 2027, meaning that every Google-blessed Android device will maintain a whitelist of ‘verified developers’, not unlike the locked-down Apple mobile ecosystem. Although Google’s claim is that this is for ‘security’, it does not prevent the regular practice of scammers buying up existing – verified – developer accounts, nor does it harden Android against unscrupulous apps. More likely is that this will wipe out Android as an actual alternative to Apple’s mobile OS offerings, especially for the hobbyist and open source developer.

CERN’s Large Hadron Collider Runs On A Bendix G-15 In 2025

August 25, 2025 by Adam Fabio 18 Comments

The Bendix G-15 refurbished by [David at Usagi Electric] is well known as the oldest fully operational digital computer in North America. The question [David] gets most is “what can you do with it?”. Well, as a general-purpose computer, it can do just about anything. He set out to prove it. Can a 1950s-era vacuum tube computer handle modern physics problems? This video was several years in the making, was a journey from [David’s] home base in Texas all the way to CERN’s Large Hadron Collider (LHC) in Switzerland.

The G-15 can run several “high-level” programming languages, including Algol. The most popular, though, was Intercom. Intercom is an interactive programming language – you can type your program in right at the typewriter. It’s much closer to working with a basic interpreter than, say, a batch-processed IBM 1401 with punched cards. We’re still talking about the 1950s, though, so the language mechanics are quite a bit different from what we’re used to today.

To start with, [Usagi’s] the G-15 is a numeric machine. It can’t even handle the full alphabet. What’s more, all numbers on the G-15 are stored as floating-point values. Commands are sent via operation codes. For example, ADD is operation 43. You have to wrangle an index register and an address as well. Intercom feels a bit like a cross between assembler and tokenized BASIC. Continue reading “CERN’s Large Hadron Collider Runs On A Bendix G-15 In 2025” →

How To Stop Zeus From Toasting Your Pi

August 22, 2025 by Heidi Ulrich 18 Comments

If you’ve ever lost gear to lightning or power spikes, you know what a pain they are. Out in rural Arkansas, where [vinthewrench] lives, the grid is more chaos than comfort – especially when storms hit. So, he dug into the problem after watching a cheap AC-DC module quite literally melt down. The full story, as always, begins with the power company’s helpful reclosers: lightning-induced surges, and grid switching transients. The result though: toasted boards, shorted transformers, and one very dead Raspberry Pi. [vinthewrench] wrote it all up – with decent warnings ahead. Take heed and don’t venture into things that could put your life in danger.

Back to the story. Standard surge suppressors? Forget it. Metal-oxide varistor (MOV)-based strips are fine for office laptops, but rural storms laugh at their 600 J limits. While effective and commonly used, MOVs are “self-sacrificing” and degrade over time with each surge event.

[vinthewrench] wanted something sturdier. Enter ZeusFilter 1.0 – a line-voltage filter stitched together from real parts: a slow-blow fuse, inrush-limiting thermistor, three-electrode gas discharge tube for lightning-class hits, beefy MOVs for mid-sized spikes, common-mode choke to kill EMI chatter, and safety caps to bleed off what’s left. Grounding done right, of course. The whole thing lives on a single-layer PCB, destined to sit upstream of a hardened PSU.

As one of his readers pointed out, though, spikes don’t always stop at the input. Sudden cut-offs on the primary can still throw nasty pulses into the secondary, especially with bargain-bin transformers and ‘mystery’ regulators. The reader reminded that counterfeit 7805s are infamous for failing short, dumping raw input into a supposedly safe 5 V rail. [vinthewrench] acknowledged this too, recalling how collapsing fields don’t just vanish politely – Lenz makes sure they kick back hard. And yes, when cheap silicon fails, it fails ugly: straight smoke-release mode.

In conclusion, we’re not particularly asking you to try this at home if you lack the proper knowledge. But if you have a high-voltage addiction, this home research is a good start to expand your knowledge of what is, in theory, possible.

Ask Hackaday: Where Are All The Fuel Cells?

August 21, 2025 by Tom Nardi 60 Comments

Given all the incredible technology developed or improved during the Apollo program, it’s impossible to pick out just one piece of hardware that made humanity’s first crewed landing on another celestial body possible. But if you had to make a list of the top ten most important pieces of gear stacked on top of the Saturn V back in 1969, the fuel cell would have to place pretty high up there.

Apollo fuel cell. Credit: James Humphreys

Smaller and lighter than batteries of the era, each of the three alkaline fuel cells (AFCs) used in the Apollo Service Module could produce up to 2,300 watts of power when fed liquid hydrogen and liquid oxygen, the latter of which the spacecraft needed to bring along anyway for its life support system. The best part was, as a byproduct of the reaction, the fuel cells produced drinkable water.

The AFC was about as perfectly suited to human spaceflight as you could get, so when NASA was designing the Space Shuttle a few years later, it’s no surprise that they decided to make them the vehicle’s primary electrical power source. While each Orbiter did have backup batteries for emergency purposes, the fuel cells were responsible for powering the vehicle from a few minutes before launch all the way to landing. There was no Plan B. If an issue came up with the fuel cells, the mission would be cut short and the crew would head back home — an event that actually did happen a few times during the Shuttle’s 30 year career.

This might seem like an incredible amount of faith for NASA to put into such a new technology, but in reality, fuel cells weren’t really all that new even then. The space agency first tested their suitability for crewed spacecraft during the later Gemini missions in 1965, and Francis Thomas Bacon developed the core technology all the way back in 1932.

So one has to ask…if fuel cell technology is nearly 100 years old, and was reliable and capable enough to send astronauts to the Moon back in 1960s, why don’t we see them used more today?

Continue reading “Ask Hackaday: Where Are All The Fuel Cells?” →

The WHY 2025 Badge And Its 18650s

August 12, 2025 by Jenny List 38 Comments

The largest European hacker camp this year was in the Netherlands — What Hackers Yearn (WHY) 2025 is the latest in the long-running series of four-yearly events from that country, and 2025 saw a move from the Flevoland site used by SHA2017 and MCH2021, back to just north of Alkmaar in Noord-Holland, where the OHM2013 event took place. WHY has found itself making the news in the Dutch technical media for all the wrong reasons over the last few days, after serious concerns were raised about the fire safety of its badge.

The cell supplied with a WHY 2025 badge, with very clear fire safety warning — This is the cell supplied with the WHY badge, complete with manufacturer’s warning.

The concerns were raised from the RevSpace hackerspace in Leidschendam, and centre around the design of the battery power traces on the PCB between the battery holders and the power supply circuitry. Because the 18650 cells supplied with that badge lack any protection circuitry, bridging the power traces could be a fire risk.

In short: their report names the cell holders as having tags too large for their pads on the PCB, a too-tight gap between positive and negative battery traces, protected only by soldermask, and the inadequacy of the badge’s short circuit protection. In the event that metal shorted these battery tags, or wore through the soldermask, the batteries would be effectively shorted, and traces or components could get dangerously hot.

The WHY organizers have responded with a printed disclaimer leaflet warning against misuse of the cells, and added a last-minute epoxy coating to the boards to offer additional protection. Some people are 3D-printing cases, which should also help reduce the risk of short-circuiting due to foreign metal objects. Using an external powerbank with short-circuit protection instead of the cells would solve the problem as well. Meanwhile a group of hackers collecting aid for Ukraine are accepting the batteries as donations.

It’s understood that sometimes bugs find their way into any project, and in that an event badge is no exception. In this particular case, the original Dutch badge team resigned en masse at the start of the year following a disagreement with the WHY2025 organizers, so this badge has been a particularly hurried production. Either way, we are fortunate that the issue was spotted, and conference organizers took action before any regrettable incidents occurred.