Homebrew PH Meter Uses Antimony Electrode

Understanding the nature of pH has bedeviled beginning (and not-so-beginning) chemistry students for nearly as long as chemistry has had students. It all seems so arbitrary, being the base-10 log of the inverse of hydrogen ion concentration and with a measurement range of 0 to 14. Add to that the electrochemical reactions needed to measure pH electronically, and it’s enough to make your head spin.

Difficulties aside, [Markus Bindhammer] decided to tackle the topic and came up with this interesting digital pH meter as a result. Measuring pH electronically is all about the electrode, or rather a pair of electrodes, one of which is a reference electrode. The potential difference between the electrodes when dipped into the solution under test correlates to the pH of the solution. [Markus] created his electrode by drawing molten antimony into a length of borosilicate glass tubing containing a solid copper wire as a terminal. The reference electrode was made from another piece of glass tubing, also with a copper terminal but filled with a saturated solution of copper(II) sulfate and plugged with a wooden skewer soaked in potassium nitrate.

In theory, this electrode system should result in a linear correlation between the pH of the test solution and the potential difference between the electrodes, easily measured with a multimeter. [Marb]’s results were a little different, though, leading him to use a microcontroller to scale the electrode output and display the pH on an OLED.

The relaxing video below shows the build process and more detail on the electrochemistry involved. It might be worth getting your head around this, since liquid metal batteries based on antimony are becoming a thing.

Continue reading “Homebrew PH Meter Uses Antimony Electrode”

Liquid Metal Battery Goes Into Production

The news is rife with claims of the next great thing in clean energy generation, but most of these technologies never make it to production. Whether that’s due to cost issues, production, or scalability, we’re often teased with industry breakthroughs that never come to fruition. Multi-layered solar panels, wave and tidal energy, and hydrogen fuel cells are all things that are real but can’t seem to break through and overtake other lower cost, simpler, and proven technologies. One that seems to be bucking this trend is the liquid metal battery, which startup Ambri is putting into service on the electrical grid next year.

With lithium ion battery installations running around $405 per kilowatt-hour, Ambri’s battery technology is already poised to be somewhat disruptive at a cost of about half that. The construction method is simpler than lithium as well, using molten metal electrodes and a molten salt electrolyte. Not only is this more durable, it’s also not flammable and is largely immune to degradation over time. The company’s testing results indicate that after 20 years the battery is expected to still retain 95% of its capacity. The only hitch in scaling this technology could be issues with sourcing antimony, one of the metals needed for this type of construction.

Even though Ambri can produce these batteries for $180 to $250 per kilowatt-hour, they need to get the costs down to about $20 for the technology to be cost-competitive with “base load” power plants (an outdated term in itself). They do project their costs to come down significantly and hit this mark by 2030, which would put electrical grids on course to be powered entirely by renewables. Liquid metal batteries aren’t the only nontraditional battery out there trying to solve this problem, though. Another promising interesting energy storage technology on the horizon is phase-change materials.

Development Tools Of The Prop-Making World

We’ve seen them before. The pixel-perfect Portal 2 replica, the Iron Man Arc Reactor, the Jedi Lightsaber. With the rise of shared knowledge via the internet, we can finally take a peek into a world hidden behind garage doors, basements, and commandeered coffee tables strewn with nuts, bolts, and other scraps. That world is prop-making. As fab equipment like 3D printers and laser cutters start to spill into the hands of more people, fellow DIY enthusiasts have developed effective workflows and corresponding software tools to lighten their loads. I figured I’d take a brief look at a few software tools that can open the possibilities for folks at home to don the respirator and goggles and start churning out props.

Continue reading “Development Tools Of The Prop-Making World”

Otherworldy CAD Software Hails From A Parallel Universe

The world of free 3D-modeling software tends to be grim when compared to the expensive professional packages. Furthermore, 3D CAD modeling software suggestions seem to throw an uproar when new users seek open-source or inexpensive alternatives. Taking a step apart from the rest, [Matt] has developed his own open-source CAD package with a spin that inverts the typical way we do CAD.

Antimony is a fresh perspective on 3D modeling. In contrast to Blender’s “free-form sculpting” and Solidworks’ sequential extrudes and cuts, Antimony invites you to break down your model into a network of both primitive geometry and operations that interact with that geometry.

Functionally, Antimony represents objects as a graphical collection of nodes that encode both primitives and operations. Want a cylinder? Start with a circle node and pipe it into an extrude node. Need to cut out some part geometry? Try defining it with one or more primitives, and then perform a boolean intersection operation. Users can even write their own nodes with custom scripts written in Python. Overall, Antimony boasts the power of parametric design similar to OpenSCAD while it also boosts readability with a graphical, rather than text-based, part description. Finally, because part geometry is essentially stored as a series of instructions, the process of modeling the part does not limit the resolution of the output .STL mesh. (Think: vector-based images, versus pixel-based images).

Current versions of the software are available for both Mac and Linux, and the entire project is open-source and available on the Githubs. (For the shrewd-eyed software developers, most of the project is written with Python that interacts with lower-level routines handled in C++ and exposed through Boost.Python.) Take a video tour of an Antimony workflow with [Matt] after the break. All-in-all, despite that the software is still in its alpha stages, it’s highly functional and (for the block-diagram fans) intuitive. We’re thrilled to put our programming hats on and try CAD from, as [Matt] coins it “a parallel universe.”

Continue reading “Otherworldy CAD Software Hails From A Parallel Universe”