Author: Donald Papp

1131 Articles

Memristors Are Cool, Radiation-resistant Memristors Even Moreso

October 5, 2024 by 9 Comments

Space is a challenging environment for semiconductors, but researchers have shown that a specific type of memristor (the hafnium oxide memristor, to be exact) actually reacts quite usefully when exposed to gamma radiation. In fact, it’s even able to leverage this behavior as a way to measure radiation exposure. In essence, it’s able to act as both memory and a sensor.

Being able to resist radiation exposure is highly desirable for space applications. Efficient ways to measure radiation exposure are just as valuable. The hafnium oxide memristor looks like it might be able to do both, but before going into how that works, let’s take a moment for a memristor refresher.

A memristor is essentially two conductive plates between which bridges can be made by applying a voltage to “write” to the device, by which one sets it to a particular resistance. A positive voltage causes bridging to occur between the two ends, lowering the device’s resistance, and a negative voltage reverses the process, increasing the resistance. The exact formulation of a memristor can vary. The memristor was conceived in the 1970s by Leon Chua, and HP Labs created a working one in 2008. An (expensive) 16-pin DIP was first made available in 2015.

A hafnium oxide memristor is a bit different. Normally it would be write-once, meaning a negative voltage does not reset the device, but researchers discovered that exposing it to gamma radiation appears to weaken the bridging, allowing a negative voltage to reset the device as expected. Exposure to radiation also caused a higher voltage to be required to set the memristor; a behavior researchers were able to leverage into using the memristor to measure radiation exposure. Given time, a hafnium oxide memristor exposed to radiation, causing it to require higher-than-normal voltages to be “set”, eventually lost this attribute. After 30 days, the exposed memristors appeared to recover completely from the effects of radiation exposure and no longer required an elevated voltage for writing. This is the behavior the article refers to as “self-healing”.

The research paper has all the details, and it’s interesting to see new things relating to memristors. After all, when it comes to electronic components it’s been quite a long time since we’ve seen something genuinely new.

See The “Pause-and-Attach” Technique For 3D Printing In Action

October 5, 2024 by 7 Comments

[3DPrintBunny] is someone who continually explores new techniques and designs in 3D printing, and her latest is one she calls “pause-and-attach”, which she demonstrates by printing a vase design with elements of the design splayed out onto the print bed.

The splayed-out elements get peeled up and attached to the print during a pause.

At a key point, the print is paused and one peels up the extended bits, manually attaching them to sockets on the main body of the print. Then the print resumes and seals everything in. The result is something that appears to defy the usual 3D printer constraints, as you can see here.

Pausing a 3D print to insert hardware (like nuts or magnets) is one thing, but we can’t recall seeing anything quite like this approach. It’s a little bit reminiscent of printing foldable structures to avoid supports in that it prints all of its own self-connecting elements, but at the same time it’s very different.

We’ve seen [3DPrintBunny]’s innovative approaches before with intentional stringing used as a design element and like the rest of her work, it’s both highly visual and definitely it’s own thing. You can see the whole process in a video she posted to social media, embedded below.

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3D Printer Swaps Build Plates To Automate Print Jobs

September 30, 2024 by 17 Comments

[Andre Me] has long-standing interest in automating 3D print jobs, and his latest project is automating build plate changes on the Bambu A1 Mini.

Here’s how it works: each build plate gets a sort of “shoe” affixed to it, with which attachments on the printer itself physically interact when loading new plates and removing filled ones.

When a print job is finished, custom G-code causes an attachment on the printer to wedge itself under the build plate and peel it off until it is freed from the magnetic bed, after which the finished plate can be pushed towards the front. A stack of fresh build plates is behind the printer, and the printer slips a new one from the bottom when needed. Again, since the printer’s bed is magnetic, all one has to do is get the new plate to reliably line up and the magnetic attraction does the rest.

Some methods of automating print jobs rely on ejecting the finished parts and others swap the print beds. [Andre]’s is the latter type and we do really like how few moving parts are involved, although the resulting system has the drawback of requiring considerably more table space than just the printer itself. Still, it’s not at all a bad trade-off.

Watch it in action in the two videos embedded below. The first shows a time-lapse of loading and ejecting over 100 build plates in a row, and the second shows the whole system in action printing bowls in different colors. Continue reading “3D Printer Swaps Build Plates To Automate Print Jobs” →

Shoot Smooth Video From Your Phone With The Syringe Slider

September 29, 2024 by 5 Comments

We love the idea [Btoretsukuru] shared that uses a simple setup called the Syringe Slider to take smoothly-tracked video footage of small scenes like model trains in action. The post is in Japanese, but the video is very much “show, don’t tell” and it’s perfectly clear how it all works. The results look fantastic!

Suited to filming small subjects.

The device consists of a frame that forms a sort of enclosed track in which one’s mobile phone can slide horizontally. The phone butts up against the plunger of an ordinary syringe built into the frame. As the phone is pushed along, it depresses the plunger which puts up enough resistance to turn the phone’s slide into a slow, even, and smooth glide. Want to fine-tune the resistance and therefore the performance? Simply attach different diameter tips to the syringe.

The results speak for themselves, and it’s a fantastically clever bit of work. There are plenty of DIY slider designs (some of which get amazingly complex) but they are rarely small things that can be easily gotten up close and personal with small subjects like mini train terrain.

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VR Headset With Custom Face Fitting Gets Even More Custom

September 28, 2024 by 7 Comments

The Bigscreen Beyond is a small and lightweight VR headset that in part achieves its small size and weight by requiring custom fitting based on a facial scan. [Val’s Virtuals] managed to improve fitment even more by redesigning a facial interface and using a 3D scan of one’s own head to fine-tune the result even further. The new designs distribute weight more evenly while also providing an optional flip-up connection.

It may be true that only a minority of people own a Bigscreen Beyond headset, and even fewer of them are willing to DIY their own custom facial interface. But [Val]’s workflow and directions for using Blender to combine a 3D scan of one’s face with his redesigned parts to create a custom-fitted, foam-lined facial interface is good reading, and worth keeping in mind for anyone who designs wearables that could benefit from custom fitting. It’s all spelled out in the project’s documentation — look for the .txt file among the 3D models.

We’ve seen a variety of DIY approaches to VR hardware, from nearly scratch-built headsets to lens experiments, and one thing that’s clear is that better comfort is always an improvement. With newer iPhones able to do 3D scanning and 1:1 scale scanning in general becoming more accessible, we have a feeling we’re going to see more of this DIY approach to ultra-customization.

See The Hands-on Details Behind Stunning Helmet Build

September 28, 2024 by 6 Comments

[Zibartas] recently created wearable helmets from the game Starfield that look fantastic, and we’re happy to see that he created a video showcasing the whole process of design, manufacture, and assembly. The video really highlights just how much good old-fashioned manual work like sanding goes into getting good results, even in an era where fancy modern equipment like 3D printing is available to just about anyone.

The secret to perfectly-tinted and glassy-smooth clear visors? Lots and lots of sanding and polishing.

The visor, for example, is one such example. The usual approach to making a custom helmet visor (like for Daft Punk helmet builds) is some kind of thermoforming. However, the Starfield helmet visors were poor candidates due to their shape and color. [Zibartas]’s solution was to 3D print the whole visor in custom-tinted resin, followed by lots and lots of sanding and polishing to obtain a clear and glassy-smooth end product.

A lot of patient sanding ended up being necessary for other reasons as well. Each helmet has a staggering number of individual parts, most of which are 3D printed with resin, and these parts didn’t always fit together perfectly well.

[Zibartas] also ended up spending a lot of time troubleshooting an issue that many of us might have had an easier time recognizing and addressing. The helmet cleverly integrates a faux-neon style RGB LED strip for internal lighting, but the LED strip would glitch out when the ventilation fan was turned on. The solution after a lot of troubleshooting ended up being simple decoupling capacitors, helping to isolate the microcontrollers built into the LED strip from the inductive load of the motors.

What [Zibartas] may have lacked in the finer points of electronics, he certainly makes up for in practical experience when it comes to wearable pieces like these. The helmets look solid but are in fact full of open spaces and hollow, porous surfaces. This makes them more challenging to design and assemble, but it pays off in spades when worn. The helmets not only look great, but allow a huge amount of airflow. This along with the fans makes them comfortable to wear as well as prevents the face shield from misting up from the wearer’s breathing. It’s a real work of art, so check out the build video, embedded just below.

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Hands-on With New IPhone’s Electrically-Released Adhesive

September 22, 2024 by 63 Comments

There’s a wild new feature making repair jobs easier (not to mention less messy) and iFixit covers it in their roundup of the iPhone 16’s repairability: electrically-released adhesive.

Here’s how it works. The adhesive looks like a curved strip with what appears to be a thin film of aluminum embedded into it. It’s applied much like any other adhesive strip: peel away the film, and press it between whatever two things it needs to stick. But to release it, that’s where the magic happens. One applies a voltage (a 9 V battery will do the job) between the aluminum frame of the phone and a special tab on the battery. In about a minute the battery will come away with no force, and residue-free.

There is one catch: make sure the polarity is correct! The adhesive releases because applying voltage oxidizes aluminum a small amount, causing Al3+ to migrate into the adhesive and debond it. One wants the adhesive debonded from the phone’s frame (negative) and left on the battery. Flipping the polarity will debond the adhesive the wrong way around, leaving the adhesive on the phone instead.

Some months ago we shared that Apple was likely going to go in this direction but it’s great to see some hands-on and see it in action. This adhesive does seem to match electrical debonding offered by a company called Tesa, and there’s a research paper describing it.

A video embedded below goes through the iPhone 16’s repairability innovations, but if you’d like to skip straight to the nifty new battery adhesive, that starts at the 2:36 mark.

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