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

May 26, 2021 by Kristina Panos 46 Comments

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.

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Iridescent Rainbow Chocolate, Just Add Diffraction Grating!

May 23, 2021 by Donald Papp 15 Comments

Chocolate plus diffraction grating equals rainbow chocolate

Here’s a great picture from [Jelly & Marshmallows] that shows off the wild effects of melted chocolate poured onto a diffraction grating. A diffraction grating is a kind of optical component whose micro-features act to disperse and scatter light. Diffraction gratings are available as thin plastic film with one side that is chock full of microscopic ridges, and the way light interacts with these ridges results in an iridescent, rainbow effect not unlike that seen on a CD or laserdisc.

It turns out that these micro-ridges can act as a mold, and pouring chocolate over a diffraction grating yields holo-chocolate. These photos from [Jelly & Marshmallows] show this effect off very nicely, but as cool as it is, we do notice that some of the letters seem a wee bit hit-or-miss in how well they picked up the diffraction grating pattern.

Fortunately, we know just what to suggest to take things to the next level. If you want to know more about how exactly this effect can be reliably accomplished, you’ll want to check out our earlier coverage of such delicious optics, which goes into all the nitty-gritty detail one could ever want about getting the best results with either melted sugar, or dark chocolate.

3D Printing Espresso Parts

May 15, 2021 by Bryan Cockfield 28 Comments

Virtually any hobby has an endless series of rabbit holes to fall into, with new details to learn around every corner. This is true for beekeeping, microcontrollers, bicycles, and gardening (just to name a few), but those involved in the intricate world of coffee roasting and brewing turn this detail dial up to the max. There are countless methods of making coffee, all with devout followers and detractors alike, and each with its unique set of equipment. To explore one of those methods and brew a perfect espresso, [Eric] turned to his trusted 3D printer and some compressed gas cylinders.

An espresso machine uses high pressure to force hot water through finely ground coffee. This pressure is often developed with an electric pump, but there are manual espresso machines as well. These require expensive parts which can withstand high forces, so rather than build a heavy-duty machine with levers, [Eric] turned to compressed CO2 to deliver the high pressure needed.

To build the pressure/brew chamber, he 3D printed most of the parts with the exception of the metal basked which holds the coffee. The 3D printed cap needs to withstand around nine atmospheres of pressure so it’s reasonably thick, held down with four large bolts, and holds a small CO2 canister, relief valve, and pressure gauge.

To [Eric]’s fine tastes, the contraption makes an excellent cup of coffee at minimal cost compared to a traditional espresso machine. The expendable CO2 cartridges only add $0.15 to the total cost of the cup and for it’s simplicity and small size this is an excellent trade-off. He plans to improve on the design over time, and we can’t wait to see what he discovers. In the meantime, we’ll focus on making sure that our beans are of the highest quality so they’re ready for that next espresso.

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Keep Coffee Warm Through Induction Heating

April 11, 2021 by Bryan Cockfield 13 Comments

Transformers have an obvious use for increasing or decreasing the voltage in AC systems, but they have many other esoteric uses as well. Electric motors and generators are functionally similar and can be modeled as if they are transformers, but the truly interesting applications are outside these industrial settings. Wireless charging is essentially an air-core transformer that allows power to flow through otherwise empty space, and induction cooking uses a similar principle to induce current flow in pots and pans. And, in this case, coffee mugs.

[Sajjad]’s project is an effort to keep his coffee warm while it sits on his desk. To build this special transformer he places his mug inside a coil of thick wire which is connected to a square wave generator. A capacitor sits in parallel with the coil of wire which allows the device to achieve resonance at a specific tuned frequency. Once at that frequency, the coil of wire efficiently generates eddy currents in the metal part of the coffee mug and heats the coffee with a minimum of input energy.

While this project doesn’t work for ceramic mugs, [Sajjad] does demonstrate it with a metal spoon in the mug. While it doesn’t heat up to levels high enough to melt solder, it works to keep coffee warm in a pinch if a metal mug isn’t available. He also plans to upgrade it so it takes up slightly less space on his desk. For now, though, it can easily keep his mug of coffee hot while it sits on his test bench.

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Smart Lid Spies On Sourdough Starter, Sends Data Wirelessly

March 4, 2021 by Donald Papp 16 Comments

[Justin Lam] created a wonderfully-detailed writeup of his Smart Sourdough Lid project, which was created out of a desire to get better data on the progress and health of his sourdough starters, and to do so more efficiently. The result is a tidy, one-piece lid that constantly measures temperature, humidity, and height of the starter in the jar. Data is sent wirelessly for analysis, but there is also a handy OLED display on the top of the lid that shows immediately useful data like how much the starter has peaked, and how much time has passed since it did so.

The PCB was optimized for size, and not designed with mounting in mind, so a hot-glued machine screw serves as a “button extender”. Issues like this can happen when enclosures are designed after the fact; it’s something to which we can all relate.

We really like how focused the design is, and the level of detail [Justin] goes into to explain his design decisions and describe how well they worked out. This isn’t [Justin]’s first kick at the can when it comes to getting data on his sourdough, after all. We remember his earlier work using computer vision to analyze sourdough starters, and he used what he learned to inform this new design; the smart lid is easier to use and handles data much more efficiently.

The project’s GitHub repository has all the information needed to build your own. The lid is ESP8266-based and integrates a VL6180X time-of-flight (ToF) distance sensor, DHT22 to sense temperature and humidity, and a small SSD1306 OLED display for data. A small custom PCB keeps the modules tidy, and a 3D-printed custom enclosure makes it one tidy package.

[Justin] also analyzes the results he obtained and talks about what they mean in the last part of his writeup, so if you’re into baking and interested in his findings, be sure to give that a look.

How To Bake Brownies With A Perfect Glossy Skin

February 14, 2021 by Lewin Day 35 Comments

If you’re anything at all like this writer, you don’t spend a lot of time inspecting brownies past the initial object identification phase, preferring to insert them directly into the mouth post-haste. But those with more of an aesthetic focus take great care to produce brownies with a glossy, attractive skin. [Adam Ragusea] decided to find out what it takes to get a perfect brownie skin, time after time.

After many, many trays of brownies, [Adam], with the assistance of [Dr. Pia Sörensen], determined that the key seems to be making a brownie mixture with very finely dissolved sugar, in sucrose form, with a carefully controlled amount of water in the mixture. This produces a thick mixture which can hold together against the gases bubbling out during the cooking process, and produces a nice glossy skin. Too much water, and the mixture isn’t viscous enough to hold up, leading to brownies full of pock marks, while alternative sugars like fructose and glucose likely disrupt the ordered structure of sucrose molecules necessary for a shiny surface.

Together, [Adam] and [Pia] do a great job of exploring the molecular chemistry behind the process, as well as ruling out several myths that have been perpetuated in the viciously insular brownie subculture. All they’re missing is a set of standardised reflectivity tests executed with an Arduino and some photodiodes, but we’ll assume that was just cut for time. We’ve seen other hacks in the realm of molecular gastronomy before, like this homebrew kitchen centrifuge. Video after the break.

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Spinach Photo Prints

February 13, 2021 by Brian McEvoy 14 Comments

Some people like spinach in their salads. Others would prefer it if it never gets near their fork. Still, other folks, like [Almudena Romero], use it for printing pictures, and they’re the folks we’ll focus on today.

Anthotypes are positive images made from plant dyes that fade from light exposure. Imagine you stain your shirt at a picnic and leave it in the sun with a fork covering part of the stain. When you come back, the stain not sheltered by cutlery is gone, but now you have a permanent fork shape logo made from aunt Bev’s BBQ sauce. The science behind this type of printmaking is beautifully covered in the video below the break. You see, some plant dyes are not suitable for light bleaching, and fewer still if you are not patient since stains like blueberry can take a month in the sun.

The video shows how to make your own plant dye, which has possibilities outside of anthotype printing. Since the dye fades in sunlight, it can be a temporary paint, or you could use samples all over your garden to find which parts get lots of sunlight since the most exposed swatches will be faded the most. Think of a low-tech UV meter with logging, but it runs on spinach.

If the science doesn’t intrigue you, the artistic possibilities are equally cool. All the pictures have a one-of-a-kind, wabi-sabi flare. You take your favorite photo, make it monochrome, print it on a transparent plastic sheet, and the ink will shield the dye and expose the rest. We just gave you a tip about finding the sunniest spot outdoors, so get staining.

Anthotype printing shares some similarities with etch-resist in circuit board printing processes, but maybe someone can remix spinach prints with laser exposure!

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