On a fundamental level a computer’s processor is composed of logic gates. These gates use the presence of electricity and lack thereof to represent a binary system of ones and zeros. You say “we already know this!” But have you ever considered the idea of using something other than electricity to make binary computations? Well, a team at Stanford University has. They’re using tiny droplets of water and bar magnets to make logic gates.
Their goal is not to manipulate information or to compete with modern ‘electrical’ computers. Instead, they’re aiming to manipulate matter in a logical way. Water droplets are like little bags that can carry an assortment of other molecules making the applications far reaching. In biology for instance, information is exchanged via Action Potentials – which are electrical and chemical spikes. We have the electrical part down. This technology could lead to harnessing the chemical part as well.
Be sure to check out the video below, as they explain their “water computer” in more detail.
[NurdRage] recently picked up a magnetic stirrer and hotplate. It’s been working great so far, but it lacks a thermometer probe. [NurdRage] thought he was getting one with the hotplate when he ordered it, he just never received one. Contacting the seller didn’t elicit a response, and reading the terribly translated manual didn’t even reveal who the manufacturer was. Figuring this was a knock-off, a bit more research revealed this hotplate was a copy of a SCILOGEX hotplate. The SCILOGEX temperature probe would cost $161 USD. That’s not cool.
The temperature probe was listed in the manual as a PT1000 sensor; a platinum-based RTD with a resistance of 1000Ω at 0°C. If this assumption was correct, the pinout for the temperature probe connector can be determined by sticking a 1kΩ resistor in the connector. When the hotplate reads 0ºC, that’s the wires the temperature probe connects to.
With the proper pin connectors found, [NurdRage] picked up a PT1000 on eBay for a few dollars, grabbed a DIN-5 connector from a 20 year old keyboard, and connected everything together. The sensor was encased in a pipette, and the bundle of wires snaked down piece of vinyl tube.
For $20 in parts, [NurdRage] managed to avoid paying $161 for the real thing. It works just as good as the stock, commercial unit, and it makes for a great video. Check that out below.
[Cody] has a nice little ranch in the middle of nowhere, a rifle, and a supply of ammunition. That’s just fine for the zombie apocalypse, but he doesn’t have an infinite supply of ammo. Twenty years after Z-day, he may find himself without any way to defend himself. How to fix that problem? He needs gunpowder. How do you make that? Here’s a plastic jug.
There are three ingredients required to make gunpowder – saltpeter, charcoal, and sulfur. The last two ingredients are easy enough if you have trees and a mine like [Cody], but saltpeter, the a source of nitrates, aren’t really found in nature. You can make nitrates from atmospheric nitrogen if you have enough energy, but [Cody] is going low tech for this experiment. He’s saving up his own urine in a compost pile, also called a niter bed. It’s as simple as putting a few grass clippings and straw on a plastic tarp, peeing on it for a few months, and waiting for nitrogen-fixing to do their thing.
[Cody] doesn’t have to wait a year for his compost pile to become saturated with nitrates. He has another compost pile that has been going for about 18 months, and this is good enough for an experiment in extracting calcium nitrate. After soaking and straining this bit of compost, [Cody] is left with a solution of something that has calcium nitrate in it. This is converted to potassium nitrate – or saltpeter – by running it through wood ash. After drying out this mess of liquid, [Cody] is left with something that burns with the addition of a little carbon.
With a source of saltpeter, [Cody] only needs charcoal and sulfur to make gunpowder. Charcoal is easy enough to source, and [Cody] has a mine with lead sulfide. He can’t quite extract sulfur from his ore, so instead he goes with another catalyst – red iron oxide, or rust.
The three ingredients are combined, and [Cody] decides it’s time for a test. He has a homebuilt musket, or a piece of pipe welded at one end with a touch hole, and has a big lead ball. With his homebrew gunpowder, this musket actually works. The lead ball doesn’t fly very far, but it’s enough to put a dent in a zombie or deer; not bad for something made out of compost.
Historically, this is a pretty odd way of making gunpowder. For most of history, people with guns have also had a source of saltpeter. During the Napoleonic Wars, however, France could not import gunpowder or saltpeter and took to collecting urine from soldiers and livestock. This source of nitrates was collected, converted from calcium nitrate to potassium nitrate, and combined with charcoal and sulfur to field armies.
Still, [Cody] has a great example of what can be done using traditional methods, and the fact that he can fire a ball down a barrel is proof enough that the niter bed he’s peeing in will produce even better gunpowder.
There’s a slew of apps out there for tracking your bike rides. If you want to monitor your ride while using the app, you’ll need it securely affixed to your bike. That’s where [Gord]’s No Dropped Calls build comes in. This aluminium mount was hand milled and anodized, which gives it a professional finish.
The mount consists of 3 parts which were machined out of stock 6061 aluminium. The plans were dreamt up in [Gord]’s head, and not drawn out, but the build log gives a good summary of the process. By milling away all of the unnecessary material, the weight of the mount was minimized.
Once the aluminium parts were finished, they were anodized. Anodization is a process that accelerates the oxidization of aluminum, creating a protective layer of aluminium oxide. [Greg] does this with a bucket of sulphuric acid and a power supply. Once the anodization is complete, the part is dyed for coloring. If you’re interested, [Gord] has a detailed writeup on home anodization.
The final product looks great, puts the phone within reach while biking, and prevents phone damage due to “dropped calls.”
When it comes to the history of medicine and drugs, Aspirin, or more properly acetyl-salicylic acid, is one of the more interesting stories. Plants rich in salicalates were used as medicines more than four thousand years ago, and in the fourth century BC, [Hippocrates] noted a powder made from willow bark was an excellent analgesic. It was only in the 1800s that acetylated salicylic acid was first synthesized. In 1897, chemists at Bayer gave this ancient remedy a new name: Aspirin. It’s on the WHO List of Essential Medicines, but somehow millions of people don’t have access to this pill found in every pharmacy.
The most common synthesis of Aspirin is salicylic acid treated with acetic anhydrate. Acetic anhydrate is used for the synthesis of heroin, and of course the availability of this heavily restricted by the DEA. Instead, [M. Bindhammer] will use a different method using salicylic acid and acetic acid. If you’re keeping track, that’s replacing a chemical on a DEA list of precursors with very strong vinegar.
[M. Bindhammer] even has a design for the lab that will produce the Aspirin, and it’s small enough to fit in a very large pocket. Everything that is needed for the production of acetyl-salicylic acid is there, including a reaction vessel with a heating element, a water/oil bath, flask, an Allihn condenser, and a vacuum filtering flask. Even if shipping millions of pills to far-flung reaches of the planet were easy, it’s still an exceptional Hackaday Prize entry.
When [Ian] first set out to create a homebrew OLED, he found chemical suppliers that wouldn’t take his money, manufacturers that wouldn’t talk to him, and researchers that would actively discourage him. Luckily for us, he powered through all these obstructions and created his own organic LED.
Since at least one conductor in an OLED must be transparent, [Ian] settled on ITO – indium tin oxide – for the anode. This clear coating is deposited on glass, allowing it to conduct electricity and you can buy it through a few interesting suppliers. For the cathode, [Ian] is using a gallium-indium-tin eutectic, an alloy with a very low melting point that allowed him to deposit a small puddle in his OLED stack.
With the anode and cathode taken care of, the only thing left was the actual LED. For this, [Ian] had some success with MEH-PPV, a polymer that is capable of electroluminescence. On top of this is a film of PEDOT:PPS, another polymer that serves to block electrons.
The resulting yellow-green blob of an OLED actually works, and is at least as good as some of the other homebrew semiconductor illumination projects we’ve seen around here. This is only a start, though, and [Ian] plans on putting a whole lot more time into his explorations of organic LEDs.
Biohackers, fire up your laser cutters. [CopabX] has developed OpenFuge: a (relatively) low-cost, open-source centrifuge from powerful hobby electronic components. If you thought the VCR centrifuge wasn’t impressive, trolls be damned— OpenFuge can crank out 9000 RPM and claims it’s capable of an impressive 6000 G’s. [CopabX] also worked in adjustable speed and power, setting time durations, and an LCD to display live RPM and countdown stats.
And it’s portable. Four 18650 lithium cells plug into the back, making this centrifuge a truly unique little build. The muscle comes from a DC outrunner brushless motor similar to the ones that can blast you around on a skateboard but with one key difference; an emphasis on RPMs over torque. We’re not sure exactly which motor is pictured, but one suggestion on the bill of materials boasts a 6000 KV rating, and despite inevitable losses, that’s blazing fast at nearly 15V.
You’ll want to see the demonstration video after the break, but also make time to swing by Thingiverse for schematics and recommended parts.