Design, fabrication & optical characterization of a low-cost #OpenSource #SpinCoater:

- #microfluidics & lab-on-a-chip device fabrication
- based on an old hard drive
- #Arduino-controlled
- cost: $30

https://doi.org/10.1021/acs.jchemed.9b00013
#DIYbio #DIYchem #lab #instruments #nanotechnology #thinfilm #LoC #PDMS #chemistry

Warum gibt es kein Open-Source-PDMS in Deutschland?

Patientendokumentationssysteme (PDMS) in der Gesundheitsbranche in Deutschland sind meines Wissens alle proprietär. Dabei könnten Open-Source-Lösungen meines Erachtens Transparenz, Zusammenarbeit, Patient:innen Sicherheit und Kosteneffizienz fördern.

Zudem entsteht die hohe IT-Komplexität in der Krankenhauslandschaft unter anderem durch einen Flickenteppich an individuellen Lösungen. Warum gibt es also noch keine gemeinsame Initiative von Kliniken? Kennt jemand ein solches Projekt?
Ich würde mich sehr dafür interessieren.

#pdms #healthcare #digitalisierung #unplugtrump #healthIT

Wird Deutschland zu einem Epic-Land?

Digitalstrategie des Gesundheitswesens: Lauterbach setzt auf Vertrauen bei #ePA | heise online https://www.heise.de/news/DMEA-Karl-Lauterbach-will-Digitalstrategie-wegen-ChatGPT-und-Co-anpassen-8978123.html #DigitalHealth #Digitalisierung #digitalization #ePD #ClinicalInformationSystem #CIS #KIS #KlinischesInformationsSystem #PDMS #PatientDataManagementSystem

The Ins and Outs of Casting Lenses from Epoxy

If you need a lens for a project, chances are pretty good that you pick up a catalog or look up an optics vendor online and just order something. Practical, no doubt, but pretty unsporting, especially when it's possible to cast custom lenses at home using silicone molds and epoxy resins.

Possible, but not exactly easy, as [Zachary Tong] relates. His journey into custom DIY optics began while looking for ways to make copies of existing mirrors using carbon fiber and resin, using the technique of replication molding. While playing with that, he realized that an inexpensive glass or plastic lens could stand in for the precision-machined metal mandrel which is usually used in this technique. Pretty soon he was using silicone rubber to make two-piece, high-quality molds of lenses, good enough to try a few casting shots with epoxy resin. [Zach] ran into a few problems along the way, like proper resin selection, temperature control, mold release agent compatibility, and even dealing with shrinkage in both the mold material and the resin. But he's had some pretty good results, which he shares in the video below.

[Zach] is clear that this isn't really a tutorial, but rather a summary of the highs and lows he experienced while he was working on these casting methods. It's not his first time casting lenses, of course, and we doubt it'll be his last -- something tells us he won't be able to resist trying this all-liquid lens casting method in his lab.

#mischacks #casting #epoxy #lens #mandrel #mirror #molding #optics #pdms #resin #silicone

Continuous Resin Printer Shows The Speed

Redditor [No-Championship-8520] aka [Eric Potempa] has come up with an interesting DIY take on the Continuous Liquid Interface Production (CLIP) process currently owned and developed by Carbon Inc.

The usual resin 3D printer you may be familiar with is quite a simple machine. The machine has only one axis, which is the vertically moving build platform. A light exposes a photosensitive resin that cures on and is then pulled up off of a transparent window, before the next layer is exposed.

Typical resin printer setup

CLIP is a continuous resin printing process that speeds up printing by removing this peeling process. It utilises a bottom membrane that is permeable to oxygen. This tiny amount of oxygen right at the boundary prevents the solidified resin from sticking to the bottom, allowing the Z axis to be moved up continuously, speeding up printing significantly.

The method [Eric] is using is based around a continuously rotating bath to keep the resin moving, replenishing the resin in the active polymerisation zone. The bottom of the bath is made from a rigid PDMS surface, which is continuously wiped with a squeegee to replenish the oxygen layer. He notes the issues Carbon are still having with getting enough oxygen into the build layer, which he reckons is why they only show prints of smaller or latticed structures. His method should fix that issue. The build platform is moved up slowly, with the part appearing in one long, continuous movement. He reports the printing speed as 280 mm/hour which is quite rapid to say the least. More details are very scarce, and the embedded video a little unclear, but as one commentator said "I think we just saw resin printing evolve!" the next snarky comment changed the "evolve" to "revolve" which made us giggle.

Now, we all know that 3D printing is not at all new, and only the expiration of patents and the timely work by [Adrian Bowyer] and the reprap team kickstarted the current explosion of FDM printers. Resin printers will likely be hampered by the same issues until something completely new kickstarts the next evolution. Maybe this is that evolution? We really hope that [Eric] decides to write up his project with some details, and we will be sitting tight waiting to pore over all the gory details. Fingers crossed!

#3dprinterhacks #3dresinprinter #pdms

Getting a Fly’s-Eye View with Microfabricated Lens Arrays

Atomic force microscopy, laser ablation, and etching with a witches brew of toxic chemicals: sounds like [Zachary Tong] has been playing in the lab again, and this time he found a way to fabricate arrays of microscopic lenses as a result.

Like many of the best projects, [Zach]'s journey into micro-fabrication started with a happy accident. It happened while he was working on metal-activated chemical etching (MACE), which uses a noble metal catalyst to selectively carve high-aspect-ratio features in silicon. After blasting at a silver-coated silicon wafer with a laser, he noticed the ablation pits were very smooth and uniform after etching. This led him to several hypotheses about what was going on, all of which he was able to test.

The experiments themselves are pretty interesting, but what's really cool is that [Zach] realized the smooth hemispherical pits in the silicon could act as a mold for an array of microscopic convex lenses. He was able to deposit a small amount of clear silicone resin into the mold by spin-coating, and (eventually) transfer the microlens array to a glass slide. The lenses are impressively small -- hundreds of them over only a couple hundred square microns -- and pretty well-formed. There's always room for improvement, of course, but for an initial attempt based on a serendipitous finding, we'd call it a win. As for what good these lenses are, your guess is as good as ours. But novel processes like these tend to find a way to be useful, and the fact that this is coming out of a home lab doesn't change that fact.

We find this kind of micro-fabrication fascinating. Whether it's making OLED displays, micro-machining glass with plasma, or even rolling your own semiconductors, we can't get enough of this stuff.

#parts #science #etching #hydrofluoricacid #mace #mems #metalassistecchemicaletching #microfabrication #molding #nitricacid #pdms #silcon #silcone #silicon

Flat-Pack Pasta: Like Ikea Furniture Without the Weird Wrench

When it comes to food packaging, there's no bigger scam than potato chip bags, right? People complain about the air (nitrogen, actually) inside, but it's there for a reason -- nitrogen pushes out oxygen, so the chips live in a state of factory-fresh dormancy until you rip open the bag and release the gas. If you want flat-pack chips, there's always those uniformly-shaped potato slurry wafers that come in a can. But even those usually manage to have a few broken ones.

On the other hand, no one complains about the extra space in their box of fusilli -- that would be silly. But seriously, successfully shipping fragile foods requires either flat packing or a lot of extra space, especially if that food comes in a myriad of fun 3D shapes like pasta does. Everybody knows that 3D pasta is superior to flat pasta because it holds sauces so much better. The pasta must be kept intact!

The great thing about pasta as a food is that it's simple to make, and it's more nutritious than potato chips. Because of these factors, pasta is often served in extreme situations to large groups of people, like soldiers and the involuntarily displaced. But storing large quantities of shapely pasta takes up quite a bit of space. And because of all that necessary air, much of the packaging goes to waste.

So what if you could keep your plethora of pasta in, say, a filing cabinet? A research team led by the Morphing Matter Lab at Carnegie Mellon University have created a way to make flat-pack pasta that springs to life after a few minutes in boiling water.

Just a few of the fun shapes they created. Image via Morphing Matter Lab

This probably goes without saying, but they were inspired by IKEA's packaging MO and sought to apply that flat-pack principle to food. The team has spent the last few years experimenting with 2D films of cellulose, protein, and starch to make them morph into 3D shapes as they absorb water. However, their method required additives, which likely wouldn't fly with consumers or pasta manufacturers. So they came up with a way to do it by stamping the pasta, which they call "groove-based transient morphing". Sounds to us like the one thing that can supplant lo-fi/hip-hop beats to study/relax to.

Why Didn't We Think of This?

We love the simple utility of this so much. It's like kerf-bending wood, or running a scissor blade along grosgrain ribbon in order to curl it. It would be dead simple to recreate this experiment at home with 3D-printed stamps, as long as you used food-safe mold release like the researchers did.

In order to find a suitable morphing mechanism for pasta, the team turned to PDMS, a silicone that is widely used to study kinetic behaviors. They experimented with groove types, weighing cuboid-shaped square wave grooves against frustrum-shaped Kit Kat side-view grooves, and found that the frustrum-shaped grooves maximized the curvature of the bent PDMS. With the morphing mechanism sorted, the researchers traded their lab coats for aprons and got to work applying it to dough.

The team starts with simple sheets of pasta made the traditional Italian way, with nothing but semolina flour and water. The dough is rolled out flat and cut down into shapes as normal, although most of them are new and exciting. Finally, they stamp the dough with pieces of plastic they designed and 3D printed, using a food-safe mold release in between. They started out with hand stamping, and as you can see in the video below, they ended up using a four-axis gantry for more precise impressions. Then it's business as usual: boil the pasta for 7-12 minutes depending on shape and thickness, and watch the morphing take place. It takes longer to soften where the grooves are, and they don't expand as much as the smooth parts. One team member took a matchbox of flat-pack pasta on a hike and cooked it over a fire to prove its utility.

Juicier Than Square Watermelons

A bit of quick research reveals that MIT had the same idea a few years ago. So why hasn't the idea taken off? Obviously, someone needs to make a Kickstarter and stand up a flat-pack pasta company.

Squares save space. Image via Red Duck Post

The question is, how much more would this pasta cost to consumers? It wouldn't have to be much, right? We were neither business nor industrial design majors, but how much could the overhead be on a company like that? Surely flat-pack pasta is an idea that wouldn't go limp, like square watermelons.

Growing watermelons inside of cube molds was supposed to be a refrigerator space-saving initiative that would make stacking a breeze. In reality, they cost $100-$200 each because they don't all grow with perfectly vertical stripes or fill the mold. And because each must be picked before they're ripe, they're basically inedible and mostly used for decoration.

We imagine that if flat-pack pasta became a thing, it wouldn't be perfect -- there would probably still be a few broken ones just like those flat-pack potato wafers. But who cares? They'll still hold sauce.

#cookinghacks #featured #greenhacks #interest #flatpack #pasta #pdms #transientmorphing