DNA Extraction With A 3D-Printed Centrifuge

[F.Lab] is really worried that we are going to prepare a DNA sample from saliva, dish soap, and rubbing alcohol in their 3D-printed centrifuge and then drink it like a shot. Perhaps they have learned from an horrific experience, perhaps biologists have different dietary requirements. Either way, their centrifuge is really cool. Just don’t drink the result. (Ed note: it’s the rubbing alcohol.)

The centrifuge was designed in Sketch-Up and then 3D printed. They note to take extra care to get high quality 3D prints so that the rotor isn’t out of balance. To get the high speeds needed for the extraction, they use a brushless motor from a quadcopter. This is combined with an Arduino and an ESC. There are full assembly instructions on Thingiverse.

[F.Lab] has some other DIY lab equipment designs, such as this magnetic stirrer. Which we assume you could use to make a shot if you wanted to. However, it’s probably not a good idea to mix lab supplies and food surfaces. Video after the break.

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“You Sank my Dysprosium!”: Periodic Table Battleship

Kids these days, they have it so easy. Back in the old days, we learned our elements the hard way, by listening to “The Elements” by Tom Lehrer over and over until the vinyl wore out on the LP. Now, thanks to [Karyn], kids can learn the elements by playing “Battleship” – no tongue-twisting lyrics required.

For anyone familiar with the classic “Battleship” game, you’ll wonder why no one thought of this before. [Karyn]’s version of the game is decidedly low-tech, but gets the job done. She printed out four copies of the periodic table, added letters to label the rows, and laminated them. A pair of tables goes into a manila file folder, the tops get clipped together, and dry-erase markers are used to mark out blocks of two to five elements to represent the ships of the Elemental Navy on the lower table. Guesses at the location of the enemy ships can be made by row and series labels for the elementally challenged, or better yet by element name. Hits and misses are marked with Xs and Os on the upper table, and play proceeds until that carrier hiding in the Actinide Archipelago is finally destroyed.

This is pure genius in its simplicity and practicality, but of course there’s room for improvement. The action-packed video after the break reveals some structural problems with the file folders, so that’s an obvious version 2.0 upgrade. And you can easily see how this could be used for other tabular material – Multiplication Table Battleship? Sounds good to us. And if your nippers catch the chemistry bug from this, be sure to take a deeper dive into the structure of the periodic table with them.

Now, if you’ll excuse me: “There’s antimony, arsenic, aluminum, selenium, and hydrogen and oxygen and nitrogen and rhenium….”

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What Can Happen When You Do Try This At Home

In somewhat of a countdown format, [John McMaster] looked back over the last few years of projects and documented the incidents he’s suffered (and their causes) in the course of doing cool stuff.

[John] starts us off easy — mis-wiring and consequently blowing up a 400V power supply. He concludes “double-check wiring, especially with high power systems”. Other tips and hazards involve situations in which we seldom find ourselves: “always check CCTV” before entering the experiment chamber of a cyclotron to prevent getting irradiated. Sounds like good advice.

hotplate[John] also does a lot of IC decapping, which can involve both heat and nasty acids. His advice includes being ready for large spills with lots of baking soda on hand, and he points out the need to be much more careful with large batches of acid than with the usual smaller ones. Don’t store acid in unfamiliar bottles — all plastics aren’t created equal — and don’t store any of it in your bedroom.

The incidents are listed from least to most horrible, and second place goes to what was probably a dilute Hydrofluoric acid splash. Keyword: necrosis. First place is a DIY Hydrochloric acid fabrication that involves, naturally, combining pure hydrogen and chlorine gas. What could possibly go wrong?

Anyway, if you’re going to do “this” at home, and we know a bunch of you are: be careful, be protected, and be prepared.

Thanks [J. Peterson] for the tip!

Don’t Understand the Periodic Table? It’s Just a Quantum Truth Table

In the wee hours of the late 17th century, Isaac Newton could be found locked up in his laboratory prodding the secrets of nature. Giant plumes of green smoke poured from cauldrons of all shapes and sizes, while others hissed  and spat new and mysterious chemical concoctions, like miniature volcanoes erupting with knowledge from the unknown. Under the eerie glow of twinkling candle light, Newton would go on to write over a million words on the subject of alchemy. He had to do so in secret because the practice was frowned upon at that time.  In fact, it is now known that alchemy was the ‘science’ in which he was chiefly interested in. His fascination with turning lead into gold via the elusive philosopher’s stone is now evident. He had even turned down a professorship at Cambridge and instead opted for England’s Director of Mint, where he oversaw his nation’s gold repository.

Not much was known about the fundamental structure of matter in Newton’s time. The first version of the periodic table would not come along for more than a hundred and forty years after his death. With the modern atomic structure not surfacing for another 30 years after that. Today, we know that we can’t turn lead into gold without setting the world on fire. Alchemy is recognized as a pseudoscience, and we opt for modern chemistry to describe the interactions between the elements. Everyone walking out of high school knows what atoms and the periodic table are. They know what the sub-atomic particles and their associated electric charges are. In this article, we’re going to push beyond the basics. We’re going to look at atomic structure from a quantum mechanical view, which will give you a new understanding of why the periodic table looks the way it does. In fact, you can construct the entire periodic table using nothing but the quantum numbers.

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Demonstrating Science at Harvard University

What if there was a job where you built, serviced, and prepared science demonstrations? This means showing off everything from principles of physics, to electronic theory, to chemistry and biology. Would you grab onto that job with both hands and never let go? That was my reaction when I met [Dan Rosenberg] who is a Science Lecture Demonstrator at Harvard University. He gave me a tour of the Science Center, as well as a behind the scenes look at some of the apparatus he works with and has built.

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Growing Copper and Silver Crystals for Art

Usually when Hackaday covers electroplating techniques, it’s to talk about through-hole PCB plating. But did you know you can use the same method to produce beautiful copper and silver crystal structures?

[Fred and Connie Libby] are kind enough to share how they make their crystals that they sell in tiny glass vials you can wear around your neck. The process is simple as you would think; it’s just an electrolyte solution, with a current passing through it, depositing the metal in an ion-exchange. Rather then stop once the part is sufficiently covered, you let the process run amok, and soon large crystal formations begin to emerge. [Fred and Connie] share their technique very briefly, so if you’re looking for a more detailed how-to guide, you can find one here.

Although silver crystals are a bit out of our budget, we wonder how large of a copper crystal could be grown? Large enough to be displayed on a coffee table? Surely such a work of art and science could be an interesting conservation piece in any hacker’s home.

Home Brew Supercapacitor Whipped Up In The Kitchen

[Taavi] has a problem – a wonky alarm clock is causing him to repeatedly miss his chemistry class. His solution? Outfit his clock radio with a supercapacitor, of course! But not just any supercapacitor – a home-brew 400 Farad supercap in a Tic Tac container (YouTube video in Estonian with English subtitles.)

[Taavi] turns out to be quite a resourceful lad with his build. A bit of hardware cloth and some stainless steel from a scouring pad form a support for the porous carbon electrode, made by mixing crushed activated charcoal with epoxy and squeezing them in a field-expedient press. We’ll bet his roommates weren’t too keen with the way he harvested materials for the press from the kitchen table, nor were they likely thrilled with what he did to the coffee grinder, but science isn’t about the “why?”; it’s about the “why not?” Electrodes are sandwiched with a dielectric made from polypropylene shade cloth, squeezed into a Tic Tac container, and filled with drain cleaner for the electrolyte. A quick bit of charging circuitry, and [Taavi] doesn’t have to sweat that tardy slip anymore.

The video is part of a series of 111 chemistry lessons developed by the chemistry faculty of the University of Tartu in Estonia. The list of experiments is impressive, and a lot of the teaser stills show impressively exothermic reactions, like the reduction of lead oxide with aluminum to get metallic lead or what happens when rubidium and water get together. Some of this is serious “do not try this at home” stuff, but there’s no denying the appeal of watching stuff blow up.

As for [Taavi]’s supercap, we’ve seen a few applications for them before, like this hybrid scooter. [Taavi] may also want to earn points for Tic Tac hacks by pairing his supercapacitor with this Tic Tac clock.

[Thanks, Lloyd!]