3D Printering: Why Is My PLA So Brittle?

August 20, 2026 by Maya Posch 28 Comments

Over the years poly(lactic acid) (PLA) – also known as polylactide – has become a popular thermoplastic for a variety of reasons. One of these reasons is that it’s easily produced from a renewable resource, i.e. lactic acid, with the resulting polymer even being compostable if you assume that your compost pile hits a steady 65°C or more, well above the polymer’s glass transition temperature (Tg).

That said, PLA by itself is a pretty crummy material, being exceedingly brittle and inferior to common alternatives like PET(G) in many metrics. Over the decades much research has gone into figuring out this material, its amorphous and crystalline states, as well as how to use plasticizers, copolymers, mechanical manipulation and PLLA/PDLA blends to produce more useful variants of PLA.

Today’s spools of thermoplastic filament that gets marketed as ‘PLA’ are the result of such engineering, though with plenty of remaining issues, as anyone who has struggled through a spool of brittle PLA filament can attest to. Although you can find plenty of tips online about how you should ‘just’ toss said spool into an filament dryer, oven or similar to bake it – with accusing fingers pointed at moisture intrusion, hydrolysis and kin – it helps to understand the fundamentals of how PLA works, and how it degrades.

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NASA Tests Featherweight Radar Antenna For SkyFall Mars Helicopters

August 19, 2026 by Maya Posch 13 Comments

After the little Mars helicopter Ingenuity blew everyone away with its performance, it was clear that a future Mars mission should involve more helicopters like it, with even more capabilities. The main proposal here is NASA’s SkyFall mission which would involve three autonomous helicopters, capable of searching for resources like water. To this end they would need a ground-penetrating radar system, with the antenna somehow folding away for landings, an idea that JPL is currently testing.

The SkyFall mission is currently penciled in to commence in 2028, following which it will be deployed from the Space Reactor-1 fission reactor-powered spacecraft based around elements of the now discarded Lunar Gateway space station. This obviously poses some uncertainties around when and if this mission will actually take place, but that doesn’t prevent JPL engineers from solving issues with these SkyFall helicopters.

As the antenna for the ground-penetrating radar extends beyond the landing legs, it was crucial that said antenna was flexible enough to simply fold in on itself like fabric. For this they used an existing flexible antenna design called Vivaldi, which was downscaled for the helicopters and subsequently tested to see how many simulated Mars landings it would be able to resist, as well as the effect of the cold nights and warm days.

We’re looking forward to seeing these SkyFall helicopters zip over the Martian surface. Maybe they can even swing by Ingenuity while they’re in the neighborhood.

Simple DIY STM32 Oscilloscope Project

August 19, 2026 by Maya Posch 18 Comments

In part one of what is intended to be a series on developing an STM32-based oscilloscope, [BTTLab] demonstrates a how to use the built-in ADC of an STM32F207 MCU to develop a straightforward single-channel oscilloscope. This can be followed along both via the YouTube video and the GitHub repository for this single-channel version.

Oscilloscope front-end protections. You want this. (Credit: BTTLab, YouTube) — Oscilloscope front-end protections. You want this.

Of course, an MCU’s ADC generally won’t hold a candle to a dedicated ADC for oscilloscope purposes – along with the typical beefy FPGA-based processing – with even a basic Rigol DS1054Z hitting a cool 1 GSPS, but the 2 MSPS at 12-bit resolution achieved by an STM32F207 isn’t shabby either. For more basic, low-frequency circuit and protocol debugging it would already be enough.

One thing briefly touched upon in the video is the front-end. The ADC’s inputs are rated for a specific voltage range, typically 0 to 3.3 V when running the MCU off 3.3 V, so you do not want to put higher or negative voltages into said ADC input. This is where measuring something like AC becomes rather tricky and you can get some exciting releases of magic smoke.

The demonstrated single-channel oscilloscope firmware uses the ST HAL, so it might be somewhat easy to target other STM32 MCUs as well, though naturally ADC performance will differ per MCU family and sometimes sub-family, so make sure to read the datasheet and programming manual before you dive in too deep.

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Joy-Cons Plus WiiMotes Make For Switch 2 Wii-Cons

August 18, 2026 by Maya Posch 5 Comments

As popular as the Nintendo Switch and its sequel are, it’s hard to argue that its click-on Joy-Con controllers are ergonomic, barring you having very uniquely shaped hands. This thought and a stack of Wii controllers led [KOUZEX] to the mad project of merging Joy-Cons and WiiMotes into what can affectionately be called Wii-Cons, or perhaps JoyMotes.

Suffice it to say that it’s not a very clean or easy mod, and you could definitely make the point that a custom PCB and 3D-printed shell would have been a lot easier. Making space for the Joy-Con’s side rail, thumb stick and PCB without simply tossing the WiiMote’s PCB was a tough ask, and these are two WiiMotes that will never connect to a Wii again.

With the WiiMote-shaped Joy-Cons working pretty well after all that work, the issue of remapping Joy-Con buttons that have no match on WiiMotes was probably the biggest headache. Here having said custom version could be rather helpful to have more control over the button layout, also to not have to keep harvesting the dwindling supply of WiiMotes to make WiiCons. It might even be possible to keep all the WiiMote functionality that way, to really blow people’s minds when you use your fancy Joy-Cons to next play a game on an original Wii.

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Using Acoustic Resonators As Thrusters For Small Robots

August 17, 2026 by Maya Posch 1 Comment

There are quite a few rather unconventional methods of propulsion, but perhaps one of the more curious approaches involved Helmholtz resonance, as demonstrated by [Junsun Hwang] et al. with a paper in Science Advances and associated summary article by EPFL’s School of Engineering.

Although probably better known from something like musical instruments, Helmholtz resonance can be used for more than creating or deadening noise. If stimulated with an external acoustic source that matches the chamber’s resonance frequency the result is a jet of air at the neck of the chamber. This acoustic actuation can thus be used for a number of applications.

In the paper a number of such applications are demonstrated, including a boat with three of these chambers for propulsion and steering, as well as a microflier (see above image) that when placed above an ultrasonic phased area will hover due to the production of this jet of air.

This microflier concept was then adapted with angled resonator chambers so that they could drive a propeller. Naturally, the produced thrust is only a fraction of a Newton so it’s essential to make these structures as light as possible, in the order of micrograms. These microfliers were created using high-resolution 3D printing, with a few iterations attempted to determine the optimal configuration.

In the case of the boat the ultrasonic transducers were directly placed on the bottom of the resonance chamber, but in the case of the microfliers the weight limitations necessitate these transducers to be external. Even if not the most practical kind of flying robot, as a demonstrator of this application of Helmholtz resonance for acoustic propulsion it’s pretty cool.

OLEDs Have Gained Brightness, Not Burn-In Resistance

August 17, 2026 by Maya Posch 17 Comments

OLED displays solve many of the problems suffered by LC displays, including color fidelity, dynamic range and power usage. That said, especially in the early days OLED gained a reputation for dim screens, short lifespans and burn-in. Over time better organic dyes were developed, along with burn-in prevention methods that have made OLEDs much closer to LCDs in terms of longevity. In a recent comparison between OLED TVs by RTings it’s however clear that between 2017 and 2023 there haven’t been any major advances beyond bumps in brightness.

The relatively dim screens were a major problem, as they prevented OLEDs from displaying HDR content. This issue has been well and truly addressed, as confirmed by RTings’ testing, but after an over 10,000 hours stress test that simulates about 10 years of regular use at maximum SDR brightness, especially static elements like the CNN TV banner happily burned in even on the newest models with all burn-in prevention measures enabled.

Here the biggest take-away is probably that even if the expected panel lifespan at full brightness is still the same, this higher brightness budget means that you can gain some lifespan by cranking the brightness way down. It’s also essential to keep features like pixel refresh cycles enabled, as demonstrated by [Hardware Unboxed] and their abuse of a QD-OLED monitor where a worst-case 6,000 hour stress-test managed to create some impressive levels of burn-in from uneven subpixel wear.

Using Starlink’s Satellites To Study Earth’s Upper Atmosphere

August 17, 2026 by Maya Posch 11 Comments

Aside from global access to cat videos, the presence of thousands of Starlink broadband internet access satellites in LEO has a very pleasant side effect for atmospheric researchers. Starlink publicly publishes near-real-time ephemeris data on its individual satellites. From this data you can deduce many details about the atmosphere at that altitude, including its density at specific altitudes at specific times, information which otherwise would be very hard to gather. Recently, this allowed [Mamoru Yamamoto] to determine the density of the thermosphere using tomography.

In a similar 2025 paper by [Zhuoliang Ou] et al. as published in Remote Sensing, this same data source was used to investigate details of the thermosphere. With Starlink publishing this data since 2021, this provides an invaluable dataset for studying this outermost part of the atmosphere.

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