Author: Bryan Cockfield

1757 Articles

MRI Resolution Progresses From Millimeters To Microns

April 20, 2023 by 15 Comments

Neuroscientists have been mapping and recreating the nervous systems and brains of various animals since the microscope was invented, and have even been able to map out entire brain structures thanks to other imaging techniques with perhaps the most famous example being the 302-neuron brain of a roundworm. Studies like these advanced neuroscience considerably but even better imaging technology is needed to study more advanced neural structures like those found in a mouse or human, and this advanced MRI machine may be just the thing to help gain better understandings of these structures.

A research team led by Duke University developed this new MRI technology using an incredibly powerful 9.4 Tesla magnet and specialized gradient coils, leading to an image resolution an impressive six orders of magnitude higher than a typical MRI. The voxels in the image measure at only 5 microns compared to the millimeter-level resolution available on modern MRI machines, which can reveal microscopic details within brain tissues that were previously unattainable. This breakthrough in MRI resolution has the potential to significantly advance understanding of the neural networks found in humans by first studying neural structures in mice at this unprecedented detail.

The researchers are hopeful that this higher-powered MRI microscope will lead to new insights and translate directly into advancements healthcare, and presuming that it can be replicated, used on humans safely, and becomes affordable, we would expect it to find its way into medical centers as soon as possible. Not only that, but research into neuroscience has plenty of applications outside of healthcare too, like the aforementioned 302-neuron brain of the Caenorhabditis elegans roundworm which has been put to work in various robotics platforms to great effect.

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A RISC-V Supercluster For Very Low Cost

April 19, 2023 by 22 Comments

As ARM continues to make inroads in the personal computing space thanks to its more modern and streamlined instruction set architecture (ISA) and its reduced power demands especially compared to x86 machines, the main reason it continues to become more widespread is how easy it is to get a license to make chips using this ISA. It’s still not a fully open source instruction set, though, so if you want something even more easily accessible than ARM you’ll need to find something like these chips running the fully open-source RISC-V ISA and possibly put them to work in a custom supercluster.

[bitluni] recently acquired a large number of CH32V003 microcontrollers and managed to configure them all to work together in a cluster. The entire array is only $2 (not including all of the other components attached to the board) so a cluster of arbitrary size is potentially possible. [bitluni] built a four-layer PCB for this project with an 8-bit bus so the microcontrollers can communicate with each other. Each chip has its own ADC and I/O that are wired to a set of GPIO pins on the sides of the board. The build is rounded out with a USB interface for programming and power.

There were a few quirks to get this supercluster up and running, including some issues with the way the reset and debug pins work on these specific microcontrollers. With some bugs like this out of the way, the entire cluster is up and running, and [bitluni] hints that his design could be easily interfaced with even larger RISC-V superclusters. As for a use for this build, sometimes clusters like these are built just to build them, but since the I/O and ADCs are accessible in theory this cluster could do anything a larger microcontroller might be able to do, only at a much lower price.

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Native Alaskan Language Reshapes Mathematics

April 18, 2023 by 83 Comments

The languages we speak influence the way that we see the world, in ways most of us may never recognize. For example, researchers report seeing higher savings rates among people whose native language has limited capacity for a future tense, and one Aboriginal Australian language requires precise knowledge of cardinal directions in order to speak at all. And one Alaskan Inuit language called Iñupiaq is using its inherent visual nature to reshape the way children learn and use mathematics, among other things.

Arabic numerals are widespread and near universal in the modern world, but except perhaps for the number “1”, are simply symbols representing ideas. They require users to understand these quantities before being able to engage with the underlying mathematical structure of this base-10 system. But not only are there other bases, but other ways of writing numbers. In the case of the Iñupiaq language, which is a base-20 system, the characters for the numbers are expressed in a way in which information about the numbers themselves can be extracted from their visual representation.

This leads to some surprising consequences, largely that certain operations like addition and subtraction and even long division can be strikingly easy to do since the visual nature of the characters makes it obvious what each answer should be. Often the operations can be seen as being done to the characters themselves, instead of in the Arabic system where the idea of each number must be known before it can be manipulated in this way.

This project was originally started as a way to make sure that the Iñupiaq language and culture wasn’t completely lost after centuries of efforts to eradicate it and other native North American cultures. But now it may eventually get its own set of Unicode characters, meaning that it could easily be printed in textbooks and used in computer programming, opening up a lot of doors not only for native speakers of the language but for those looking to utilize its unique characteristics to help students understand mathematics rather than just learn it.

Building An Electron Microscope For Research

April 14, 2023 by 10 Comments

There are a lot of situations where a research group may turn to an electron microscope to get information about whatever system they might be studying. Assessing the structure of a virus or protein, analyzing the morphology of a new nanoparticle, or examining the layout of a semiconductor all might require the use of one of these devices. But if your research involves the electron microscope itself, you might be a little more reluctant to tear down these expensive devices to take a look behind the curtain as the costs to do this for more than a few could quickly get out of hand. That’s why this research group has created their own electron detector.

Specifically, the electron detector is designed for use in a scanning electron microscope, which is typically used for inspecting the surface of a sample and retrieving a high-resolution, 3D image of it compared to transmission microscopes which can probe internal structures. The detector is built on a four-layer PCB which includes the photodiode sensing array, a series of amplifiers, and a power supply. All of the circuit diagrams and schematics are available for inspection as well thanks to the design being licensed under the open Creative Commons license. For any research team looking to build this, a bill of materials is also included, as is a set of build instructions.

While this is only one piece of the puzzle surrounding the setup and operation of an electron microscope, its arguably the most important, and also greatly lowers the barrier of entry for anyone looking to analyze electron microscope design themselves. With an open standard, anyone is free to modify or augment this design as they see fit which is a marked improvement over the closed and expensive proprietary microscopes out there. And, if low-cost microscopes are your thing be sure to check out this fluorescence microscope we featured that uses readily-available parts to dramatically lower the cost compared to commercial offerings.

Low-Cost Display Saved By RP2040

April 14, 2023 by 23 Comments

Anyone looking for components for electronics projects, especially robotics, microcontrollers, and IoT devices, has likely heard of Waveshare. They are additionally well-known suppliers of low-cost displays with a wide range of resolutions, sizes, and capabilities, but as [Dmitry Grinberg] found, they’re not all winners. He thought the price on this 2.8-inch display might outweigh its poor design and lack of documentation, and documented his process of bringing it up to a much higher standard with a custom driver for it.

The display is a 320×240 full-color LCD which also has a touchscreen function, but out-of-the-box only provides documentation for sending data to it manually. This makes it slow and, as [Dmitry] puts it, “pure insanity”. His ultimate solution after much poking and prodding was to bit-bang an SPI bus using GPIO on an RP2040 but even this wasn’t as straightforward as it should have been because there are a bunch of other peripherals, like an SD card, which share the bus. Additionally, an interrupt is needed to handle the touchscreen since its default touch system is borderline useless as well, but after everything was neatly stitched together he has a much faster and more versatile driver for this display and is able to fully take advantage of its low price.

For anyone else attracted to the low price of these displays, at least the grunt work is done now if a usable driver is needed to get them up and running. And, if you were curious as to what [Dmitry] is going to use this for, he’s been slowly building up a PalmOS port on hardware he’s assembling himself, and this screen is the perfect size and supports a touch interface. We’ll keep up with that project as it progresses, and for some of [Dmitry]’s other wizardry with esoteric displays make sure to see what he’s done with some inexpensive e-ink displays as well.

It’s Opposite Day For This Novel Wankel Engine

April 14, 2023 by 28 Comments

The Wankel engine seems to pop up in surprising places every so often, only to disappear into the ether before someone ultimately resurrects it for a new application and swears to get it right this time. Ultimately they come across the same problems that other Wankels suffered from, namely poor fuel efficiency and issues with reliability. They do have a surprising power-to-weight ratio and a low parts count, though, which is why people keep returning to this well, although this time it seems like most of the problems might have been solved simply by turning the entire design inside out.

A traditional Wankel engine has a triangular-shaped rotor that rotates around a central shaft inside an oval-shaped housing. This creates three chambers which continually revolve around inside the engine as the rotor spins. The seals that separate the chambers are notoriously difficult to lubricate and maintain. Instead of using a rotor inside of a chamber, this design called the X-Engine essentially uses a chamber inside of a rotor, meaning that the combustion chamber and the seals stay in fixed locations instead of spinning around. This allows for much better lubrication of the engine and also much higher efficiency. By flipping the design on its head it is able to maintain a low moving parts count, high compression ratio, and small power-to-weight ratio all while improving reliability and performance and adding the ability to directly inject fuel rather than rely on carburetion or other less-ideal methods of fuel delivery that other Wankels require.

Astute internal combustion aficionados will note that this engine is still of a two-stroke design, and thus not likely to fully eliminate the emissions problems with Wankels in a way that is satisfactory to regulators of passenger vehicles. Instead, the company is focusing on military, commercial, and aerospace applications where weight is a key driver of design. We’ve seen time and time again how the Wankel fails to live up to its promises though, and we hope that finally someone has cracked the code on one that solves its key issues.

Electric Volkswagen Adds Rooftop Solar

April 13, 2023 by 46 Comments

Volkswagen has continually teased the release of a new Microbus in the same way that Duke Nukem Forever strung us all along in the 00s, but unlike the fated video game it seems as though Volkswagen is finally building a hip new van rather than continually teasing its release year after year. With the clunky name of I.D. Buzz, European drivers can expect to see them later this year while those in the North American market will have to wait until 2024. That release will have a camper-equipped option though, but you may also want to equip yours with some solar panels as well.

The German tuning shop ABT is behind this design, which adds 600 watts of solar fixed to the top of the van. The solar roof will generate electricity largely to power the van’s auxiliary systems and is being aimed at those who are looking to outfit this van as a camper and need something to power things like refrigerators, interior lighting, and various electronics while on extended stays. There is also some mention of a 1000 watt option but with the limited space available on the roof may involve a side panel of some sort.

ABT is also noting that this system can be used to extend the driving range and, while technically true, don’t expect to be driving an I.D. Buzz on entirely solar power unless you’re willing to let it sit to charge the battery for days at a time. Like other solar installations on vehicles we’ve seen from various ingenious builders, the lack of real estate available on passenger vehicles limits their use largely to auxiliary electrical loads, but it can be possible to drive a vehicle on solar energy alone with the right design.