Making Photovoltaic Solar Cells With A Microwave

October 19, 2026 by 1 Comment

Although solar panels may seem like a kind of magic, they’re really quite simple devices, in their silicon form featuring nothing but the p-type silicon wafer and an n-type layer doped with e.g. phosphorus. Because of this simplicity it’s quite possible to make your own solar cells at home using only a few basic, off-the-shelf ingredients and a kiln, which in this recent video by [Dr. Semiconductor] uses a microwave kiln and thus justifies the video’s title.

Even the silicon wafer that you start with can be easily purchased online, though you have to be careful that it’s a bare wafer, without existing etchings on it. On this you need to get a phosphorus-rich layer, which is done by creating a delicious mixture of 1 mL of tetraethyl orthosilicate (TEOS), 0.3 mL of 85 wt% phosphoric acid, 5 mL of ethanol and 0.25 mL of distilled water. After low heat boiling this for 30 minutes, it is spincoated onto the cut square of silicon wafer using a spinning platform, like a PC fan.

Next, you shove the coated silicon into the kiln and put it into the microwave to bake at a fairly low power level for half an hour. In the video it took less than 50% power of the microwave to not melt the silicon, so remember that those microwave kilns get pretty hot.

With the delightful smells of freshly baked silicon now teasing your nostrils, you can then take out the doped silicon to sand or etch off the thin layer of glass that’s formed around the new PV cell. On the clear spots you can now put a gallium-indium contact on the p-type Si side and a wad of indium on the newly doped Si-P side, which are now your contacts for the PV cell.

The full recipe along with many of the issues discussed in the video can also be found on the blog article, though the video conclusion notes that many improvements are still possible. The created PV cell in the video reaches an efficiency of about 5%, but this could be improved through changes like the use of a clean-room, adding an anti-reflection coating and improving the contact with the cell.

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An RV On A Bike

October 19, 2026 by 2 Comments

Bicycles are the ultimate form of transportation freedom. They’re easy to repair, parts are cheap, and they will travel almost anywhere for free, as long as the rider has enough calories. Their only real downside is dealing with car-dependent societies, but once a year there’s a place in the American desert that eschews all of this and [Attoparsec] decided to take this custom cargo bike modified into an RV out to Burning Man, a place and time that would be perfect for a build like this.

The build started out as a cargo bike, but not many of them have cargo areas long enough to support a sleeping human. To increase this storage capacity, the bed was extended towards the rear. Without moving the axle further back, though, this created a problem with tail-heaviness so two trailer jacks with wheels were added to the back to keep it from occasionally tipping up too far. The sleeping enclosure was built with rigid foam insulation and taped together, in a modified style common to the Burning Man event which helps keep out sun and playa dust. The bicycle recived one last upgrade to the chain to support the extra weight, and a solar-powered refrigerator, and then it was off to the desert.

The bike RV worked well in the end, and even handled a rain storm without the roof leaking. There were some problems with the customized drive train which were solved in the short term by pounding on one of the wheels occasionally with a hammer. [Attoparsec] left the event early for other reasons, though, and might not be back for a while. But vehicles like these are gaining in popularity, presuming there are safe places to ride them. [Paul Elkins] is often making ones like this gas-powered bicycle and trailer camper.

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Meshtastic Sniffer For DragonOS

October 19, 2026 by No comments

Meshtastic has gained a lot of popularity over the last few years thanks to its low barrier of entry. No licenses are needed and the hardware is dirt cheap, at least when compared to a lot of ham radio gear. But while that physical barrier is low, there is a bit of a learning curve. Part of that comes from the fact that there are a lot of channels and modes that people could be communicating on, and unless the user knows that information up front it can be hard to find where the conversations are happening. [cemaxecuter] noticed this problem and built a Meshtastic sniffer into his radio-forward Linux distribution, DragonOS.

The sniffing software is built in C and comes as a complete standalone binary and does not rely on GNU Radio. With DragonOS up and running and the software loaded, it can look at the entire bandwidth that Meshtastic operates on and detect any traffic and decode it (as long as the key is known). [cemaxecuter] is using a HackRF as a software-defined radio for this project, which he notes doesn’t quite have enough bandwidth to cover every Meshtastic operating frequency, but it can get most of them. After firing up his own node, the software quickly detects it and shows its details in the terminal.

Software like this opens up a lot of opportunities for things that would be tedious, difficult, or impossible to do with with a standard Meshtastic node. Besides finding places where conversations are happening more easily, [cemaxecuter] also suggests that it could be used for wardriving and for locating or finding other networks much more easily. For those who still haven’t tried it out, take a look at this 2023 treatise on the protocol and hardware and then dive right in.

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An Open Micro-Maniplulator Improved

October 19, 2026 by 1 Comment

If you need a micro-manipulator, you probably already have a good idea of what it does. For example, you might be moving a probe over an IC die or wafer. You might be looking at something through a microscope. The key is moving something in very small, precise increments along three axes. An open-source design for a micro-manipulator has seen significant improvements lately. You can see several videos about the device below.

The device uses stepper motors, parallel kinematics, and miniature ball joints to achieve precise motion. The recent version 4.0 update fixes a few problems. According to the GitHub page:

  • Self-collision during homing fixed.
  • Connection of the ball joint block with screws only was not well constrained and could be rotated a bit.
  • No reliable way to ensure consistent linkage rod length
  • Unnecessary ball joint friction
  • Accurate ball position heavily dependent on print quality and corner rounding
  • Rubber bands could not be changed or removed once glued in.

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One-stop Tool Shows Apple Intelligence The Door

October 19, 2026 by 9 Comments

Don’t want AI features on your Mac? Tough luck, unless one wants to imperfectly do it by hunting down settings in about a dozen different places. Even then, the multi-gigabyte models stay on disk. Unsatisfied by this state of affairs, [omlahore] created RemoveMacAI, a one-stop-shop debloater that shows Apple Intelligence the door, reclaiming its disk space on the way out.

With RemoveMacAI one has a single location from which to turn individual AI features off, delete the models behind them, and block MacOS from downloading them again by redirecting attempts to a closed local port.

What’s refreshingly nice about the tool is how transparent it is about what each setting or preset will change, and communicates clearly what exactly one loses access to by disabling it. Want it all gone? Easy. Use one or two features, but don’t want the rest? No problem. All changes are shown up-front before the tool changes anything, and all alterations are reversible.

Released only a couple weeks ago, to say the tool is popular would be an understatement. Windows 11 also got a “remove AI features” tool, and it requires constant updating to stay functional. Will a future MacOS update interfere similarly with RemoveMacAI? Probably, but one thing that is clear is that a tool like this resonates deeply with a nontrivial number of users.

Charlotte’s New Runway Gets A Digital Twin

October 19, 2026 by No comments

The first viable powered aircraft predated the first proper runway by two decades. While it’s entirely possible to launch some planes from austere dirt or grass strips, the aviation world eventually realized that aircraft would be better off launching from a flat, paved surface.

Over the years, paving technology has gradually improved in the aviation world as it has for roads and highways. Now, there’s a project being built in Charlotte with new digital features that hopes to push the state of the art of runways even further.

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An LCR Meter With Compromises

October 19, 2026 by 8 Comments

YouTube, like the Internet, has its plusses and minuses. On the plus side, you can find information on just about anything. On the minus side, you don’t always know if that information is of any value. On the plus side, you can connect to experts who have an uncanny knack for explaining things. On the negative side, you can find people who — let’s just say aren’t. Lucky for us, [Kerry Wong] is very knowledgeable about test instruments, so when we see a review from him, like the one for the ZOYI ZT-XC1 LCR meter and multimeter, we know we will get good information. Check out that review in the video below.

It used to be unusual to have an LCR meter that could measure inductance or capacitance in a home lab. But now it isn’t a big deal, and many multimeters and testers can at least attempt to read these quantities.

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