Scientists found a surprising amount of lead in a glacier. They were studying atmospheric pollution by sampling ice cores taken from Alpine glaciers. The surprising part is that they found more lead in strata from the late 13th century than they had in those deposited at the height of the Industrial Revolution. Surely mediaeval times were supposed to be more about knights in shining armour than dark satanic mills, what on earth was going on? Why was the lead industry in overdrive in an age when a wooden water wheel represented high technology?
The answer lies in the lead smelting methods used a thousand miles away from that glacier, and in the martyrdom of a mediaeval saint.
In microfluidics, there are “drop on demand” instruments to precisely deposit extremely small volumes (pico- or nano-liters) of fluid. These devices are prohibitively expensive, so [Kyle] set out to design a system using hobbyist-level parts for under $1000. As part of this, he has a fascinating use case for a specialized camera: capturing the formation and shape of a micro-drop as it is made.
There are so many different parts to this effort that it’s all worth a read, but the two big design elements come down to:
Making the microdrop using a piezo element
Ensuring the drop is made correctly, and visually troubleshooting
Working prototype. The piezo tube is inside the blue piece at the top. The camera is to the right, and the LED strobe is on the left.
It’s one thing to make an inkjet element in a printer work, but it’s quite another to make a piezoelectric element dispense arbitrary liquids in a controlled, repeatable, and predictable way. Because piezoelectric elements force liquid out with a mechanical motion, different liquids require different drive signals and that kind of experimentation requires a way to see what is going on, hence the need for a drop observation camera.
[Kyle] ended up taking the lens assembly from a cheap USB microscope and mating it to his Korukesu C1 USB Camera with a 3D printed assembly. Another 3D printed enclosure doubles as a lightbox, holding the piezo tube in the center with the LED strobe and camera on opposite sides. The whole assembly had a few false starts, but in the end [Kyle] seems pretty happy with his results. The device is briefly described at a high level here. There are some rough edges, but it’s a working system.
Inkjet technology has been around for a long time (you can see a thirty-plus year old inkjet printer in action here) but it’s worth mentioning that not all inkjet heads are alike. Most inkjet printer heads operate thermally, which means a flash of heat vaporizes some ink to expel a micro-drop. These heads aren’t very suitable for microfluidics because not only do they rely on vaporizing the liquid, but they also don’t work well with anything other than the ink they’re designed for. Piezoelectric print heads are less common, but are more suited to the kind of work [Kyle] is doing.
For most of human history, the way to get custom shapes and colors onto one’s retinas was to draw it on a cave wall, or a piece of parchment, or on paper. Later on, we invented electronic displays and used them for everything from televisions to computers, even toying with displays that gave the illusion of a 3D shape existing in front of us. Yet what if one could just skip this surface and draw directly onto our retinas?
Admittedly, the thought of aiming lasers directly at the layer of cells at the back of our eyeballs — the delicate organs which allow us to see — likely does not give one the same response as you’d have when thinking of sitting in front of a 4K, 27″ gaming display to look at the same content. Yet effectively we’d have the same photons painting the same image on our retinas. And what if it could be an 8K display, cinema-sized. Or maybe have a HUD overlay instead, like in video games?
In many ways, this concept of virtual retinal displays as they are called is almost too much like science-fiction, and yet it’s been the subject of decades of research, with increasingly more sophisticated technologies making it closer to an every day reality. Will we be ditching our displays and TVs for this technology any time soon?
NASA would like you to help them explore — not space — but the bottom of the ocean. For now, you’ll need an Apple device, although an Android version is in the works. While it might seem strange for the space agency to look underwater, the images they need to process are from fluid-lensing cameras that use techniques originally meant to remove distortion from the atmosphere from pictures of outer space. Turns out they can also unravel distortion caused by the ocean and clearly image coral reefs.
The phone app is in the form of a game and, according to NASA, even a first grader could play it. In the game, you are in command of an ocean research vessel, the Nautilus. You dive to examine coral and identify what you see. The game generates training data for a supercomputer at the Ames Research Center so it can recognize coral types even when taken with more conventional cameras.
After three years of online publications, HardwareX may have solidified itself as an academic journal for open-source hardware. We originally wrote about HardwareX back in 2016. At the time, HardwareX hadn’t even published its first issue and only begun soliciting manuscripts. Now after three years of publishing, six issues as of October 2019 (with the seventh scheduled for April 2020), and an impact factor of 4.33, it’s fair to say that Elsevier’s push into open-access publications is on a path to success.
To give you a bit of background, HardwareX aims to promote the reproducibility of scientific work by giving researchers an avenue to publish all the hardware and software hacks that often get buried in traditional manuscripts. The format of HardwareX articles is a bit different than most academic journals. HardwareX articles look more like project pages similar to Hackaday.io. (Maybe we inspired them a bit? Who knows.)
Generating electricity out of thin air is the fantasy for our modern technology dependant world, but still falls squarely in the world of science fiction. However, researchers from the University of Massachusetts Amherst claim that they have found a way to do exactly that, using protein nano-wires to produce tiny amounts of electricity from ambient humidity.
The protein nano-wires in question are harvested from the microbe Geobacter sulfurreducens, to create a 7 µm thick film that is placed between two gold electrodes. One electrode completely covers the back of the film, while the front electrode covers only a tiny portion of the surface area. When the film is exposed ambient moisture, researchers measured 0.4 V – 0.6 V produced continuously for more than two months. The current density was about 17 µA/cm². This is only a fraction of the output of a commercial solar panel, but it can be layered with air gaps in between. The electricity is supposedly produced due to a moisture gradient through the thickness of the film. Harvesting energy using ambient humidity is not new, but the improvement in power density on this study is at least two orders of magnitude larger than that of previous studies.
The researches have named the technology Air-Gen and hope to develop it commercially. As we have seen many times before, promising lab results often don’t translate well into real world products, but this technology is definitely interesting.
We’ll continue to see all sorts of weird and wonderful ways to free up electrons, like using sweat, but we’ll have to wait and see what sticks.
The novel coronavirus sweeping the globe has led governments to institute widespread quarantines to stem the spread. Many industries have slowed production or shutdown entirely, and economic activity has slowed to a crawl. This has naturally led to a sudden reduction in greenhouse gas emissions. But how great will the effect be, and will it buy us any real time?
On The Ground
Nitrogen dioxide levels in China have dropped sharply with the reduction in industrial activity due to COVID-19. Image source: NASA
In the wake of COVID-19, good news stories have sprung up as people look for a silver lining. Unfortunately, these stories aren’t always true. There aren’t dolphins in the waters of Venice, though the water has cleared due to reduced boat activity. And drunken elephants did not begin roaming the mountains of China.
On the surface of it, these are all promising numbers. Many are cautiously optimistic that this could be a major development to help stave off the worst of climate change for a little longer. Nonetheless, it’s early days yet, and what happens after the crisis passes is just as important as what’s happening now.
