The LED is one of those fundamental building block components in electronics, something that’s been in the parts bin for decades. But while a simple LED costs pennies, that WS2812 or other fancy device is a bit expensive because internally it’s a hybrid of a silicon controller chip and several LEDs made from other semiconductor elements. Incorporating an LED on the same chip as its controller has remained something of a Holy Grail, and now an MIT team appear to have cracked it by demonstrating a CMOS device that integrates a practical silicon LED. It may not yet be ready for market but it already displays some interesting properties such as a very fast switching speed. Perhaps more importantly, further integration of what have traditionally been discrete components would have a huge impact on reducing manufacturing costs.
Anyone who has read up on the early history of LEDs will know that the path from the early-20th-century discoveries of semiconductor luminescence through the early commercial devices of the 1960s and up to the bright multi-hued devices of today has been a long one with many stages of the technology reaching the market. Thus these early experimental silicon LEDs produce light in the infrared spectrum often useful in producing sensors. Whether we’ll see an all-silicon Neopixel any time soon remains to be seen, but we can imagine that some sensors using LEDs could be incorporated on the same die as a microcontroller. It seems there’s plenty of potential for this invention.
This research was presented earlier this month at the IEDM Conference in a talk entitled Low Voltage, High Brightness CMOS LEDs. We were not able to find a published paper, we’d love read deeper so let us know in the comments below if you have info on when this will become available. In the meantime, anyone with any interest in LED technology should read about Oleg Losev, the inventor of the first practical LEDs.
Who doesn’t love epoxy? Epoxy resins, also known as polyepoxides, are an essential adhesive in many applications, both industrially and at smaller scales. Many polyepoxides however require the application of heat (around 150 °C for most types) in order to cure (harden), which can be complicated when the resin is applied to or inside layers of temperature sensitive materials. Now researchers at Nanyang Technological University (NTU) in Singapore have found a way to heat up resins using an alternating magnetic field (PDF), so-called magnetocuring.
As detailed in the research article by R. Chaudhary et al., they used commercially available epoxy resin and added nano particles of a MnxZn1-xFe2O4 alloy. This mixture was exposed to an alternating magnetic field to induce currents in the nano particles and subsequently produce heat that served to raise the temperature of the surrounding resin to about 160 °C in five minutes, allowing the resin to cure. There is no risk of overheating, as the nano particles are engineered to reach their Curie temperature, at which point the magnetic field no longer affects them. The exact Curie temperature was tweaked by changing the amount of manganese and zinc in the alloy.
After trying out a number of different alloy formulations, they settled on Mn0.7Zn0.3Fe2O4 as the optimal formulation at which no resin scorching occurred. As with all research it’s hard to tell when (and if) it will make it into commercial applications, but if this type of technology works out we could soon be gluing parts together using epoxy resin and an EM field instead of fumbling with the joys of two-component epoxy.
Last year [Emil] found themselves in the situation where a SEGGER J-link debug probe suddenly just stopped working. This was awkward not only because in-circuit debuggers are vital pieces of equipment in embedded firmware development, but also because they’re not that cheap. This led [Emil] to take the device apart to figure out what was wrong with it.
After checking voltages on the PCB, nothing obvious seemed wrong. The Tag-Connect style JTAG header on the PCB appeared to be a good second stop, requiring only a bit of work to reverse-engineer the exact pinout and hook up an ST-Link V2 in-circuit debugger to talk with the STM32F205RC MCU on the PCB. This led to the interesting discovery that apparently the MCU’s Flash ROM had seemingly lost the firmware data.
Fortunately [Emil] was able to flash back a version of the firmware which was available on the internet, allowing the J-Link device to work again. This was not the end of the story, however, as after this the SEGGER software was unable to update the firmware on the device, due to a missing bootloader that was not part of the firmware image.
Digging further into this, [Emil] found out a whole host of fascinating details about not only these SEGGER J-Link devices, but also the many clones that are out there, as well as the interesting ways that SEGGER makes people buy new versions of their debug probes.
Sticking a Raspberry Pi in a Pelican-style case and calling it a cyberdeck has become something of a meme these days, and while we certainly don’t look down on such projects, we recognize they can get a bit repetitive. But we think this one is unique enough to get a pass. Sure [eizen6] mounted a Pi inside of a rugged waterproof case, but it’s simply serving as a display for the real star of the show: a vintage Atari 800XL computer.
The overall look of the build, from the stenciled Nostromo on the back to the self-destruct warning sticker over the display is a reference to Alien. Partly because both the film and the Atari 800 were released in 1979, but also because [eizen6] says this particular aesthetic is simply the way computers should look. The visual style is also meant to signify that the project embraces the old ways despite the sprinkling of modern technology.
To that end, retro aficionados will be happy to hear that the Atari appears to be completely unmodified, with [eizen6] going as far as nestling the nearly 40 year old computer in foam rather than permanently mounting it to the case. The various cables for power, video, and data have all been terminated with the appropriate connectors as well, so everything can be easily unplugged should the 8-bit machine need to be returned to more pedestrian use.
In the top half of the case, [eizen6] has mounted the Raspberry Pi 3B+, a seven inch touch screen, a USB hub, and a SIO2SD that allows loading Atari disk images from an SD card. Using a USB capture device, video from the Atari can be shown on the Pi’s display with a simple VLC command. With a USB keyboard plugged into the hub, the Pi can be put to more advanced use should the need arise. It’s also worth noting that, thanks to a custom cable, the Atari is running off of a USB power bank. With a second USB power bank dedicated to running the Pi and its LCD display, this retro cyberdeck is fully mobile.
The newly-announced aerospace project, led by retired astronaut and engineer Prof Takao Doi, plans to launch satellites built from wood in order to reduce space debris and hazardous substances resulting from re-entry. We’re somewhat skeptical on the hazardous substances angle (and we’re not alone in this), but certainly as a way to help ensure complete burn up upon re-entry, wood is an interesting material. It also achieves a great strength to weight ratio and as a renewable resource it’s easy to source.
Prof Doi has been studying the use of wood in space for several years now. Back in 2017 he began basic research on the usability of timbers in space (pg 16), where his team experimented with coniferous (cedar and cypress) and hardwood (satinwood, magnolia, and zelkova) trees in vacuum environments. Based on successes, they predicted wooden satellite launches in the mid 2020s (their announcement this month said 2023). Sumitomo engineers have not released what kind of wood(s) will finally be used on the satellite.
You might remember Astronaut Doi from an experiment aboard the ISS where he successfully demonstrated flying a boomerang in space (video below), and he’s also discovered two supernovae in his spare time. We wish him good luck.
It is not uncommon for a Hackaday writer to trawl the comments section of a given article, looking for insights or to learn something new. Often, those with experience in various fields will share kernels of knowledge or raise questions on a particular topic. Recently, I happened to be glazing over an article on aluminium casting with interest, given my own experience in the field. One comment in particular caught my eye.
And no, the water won’t cause a steam explosion. There’s a guy on youtube (myfordlover, I think) who disproves that myth with molten iron, pouring the iron into water, pouring water into a ladle of molten iron and so on. We’ll be happy to do a video demonstrating this with aluminum if so desired.
Having worked for some time in an aluminium die casting plant, I sincerely hope [John] did not attempt this feat. While there are a number of YouTube videos showing that this can be done without calamity, there are many showing the exact opposite. Mixing molten aluminium and water often ends very poorly, causing serious injury or even fatalities in the workplace. Let’s dive deeper to see why that is.
The video published by Boston Dynamics shows off a range of their advanced robots moving as if they were humans, greyhounds, and ostriches made of actual flesh. But of course they aren’t, which explains the safety barriers surrounding the dance floor and that lack of actual audio from the scene. After picking our jaws up off the floor we began to wonder what it sounds like in the room as the whine of motors must certainly be quite impressive — check out the Handle video from 2017 for an earful of that. We also wonder how long a dance-off of this magnitude can be maintained between battery swaps.
Anthropomorphism (or would it be canine-pomorphism?) is trending this year. We saw the Spot robot as part of a dance routine in an empty baseball stadium back in July. It’s a great marketing move, and this most recent volley from BD shows off some insane stunts like the en pointe work from the dog robot while the Atlas humanoids indulge in some one-footed yoga poses. Seeing this it’s easy to forget that these machines lack the innate compassion and empathy that save humans from injury when bumping into one another. While our robotic future looks bright, we’re not in a rush to share the dance floor anytime soon.