These researchers are taking this development so seriously we can’t help but be suspicious that, perhaps, they are all deeply embroiled in a bet to see who could get funding for and complete research in the most absurd technological advancement.
Most of us have had a science teacher desperately try to alleviate the drudgery of standardized test centric science education by dramatically putting a copper nail and a zinc nail into a potato or lemon. “Behold, we can measure a voltage with this voltmeter. If you get asked what a voltmeter is on a test, here is a definition none of you have enough experimental basis to understand,” the teacher would say as their dreams of being a true educator were crushed a little more.
It’s been said that with enough soap, one could blow up just about anything. A more modern interpretation of this thought is that with enough knowledge of chemistry, anything is possible. To that end, [Peter] has certainly been doing a good job of putting his knowledge to good use. He recently worked out a relatively inexpensive and easy way to etch metals using some chemistry skill and a little bit of electricity.
After preparing a set of stencils and cleaning the metal work surface, [Peter] sets his work piece in a salt solution. A metal bar is inserted in the other end of the bath, and both it and the work piece are connected to electrodes. The flow of electricity removes some metal from the exposed work surfaces, producing whatever patterns [Peter] wants.
One interesting thing that [Peter] found is that the voltage must stay under 6 volts. This is probably part of the reason it’s relatively easy to etch with even a wall wort. Above that, the iron work piece produces a different ion which can clog the work surface and create undesirable effects. Additionally, since his first experiments with this process he has upgraded the salt bath with magnetic stirrers. He also gets the best results in a very cold environment.
There are many other uses for etching metals, too. Creating your own printed circuit boards comes to mind, but there are plenty of other uses as well. What will you do with this technique?
Looking at the ingredient list of some popular processed foods will produce a puzzled look on the typical hacker’s face. Tricalcium phosphate, thiamine mononitrate, zinc proteinate, pyridoxine hydrocloride… just who the hell comes up with these names anyway? It turns out that there is a method to the madness of chemical name structures. Some of them are well known, such as sodium chloride (NaCl) and hydrogen peroxide (H2O2). Others… not so much. In the early years of chemistry, chemical substances were named after their appearance, affects and uses. Baking soda, laughing gas and formic acid (formic is Latin for ant, and responsible for the sting in an ant bite) to name a few. As more and more chemical substances were discovered over time, a more structured naming convention was needed. Today, the above are known as sodium bicarbonate (NaHCO3), nitrous oxide (N2O) and a type of carboxylic acid (R – COOH, think of the “R” as a variable) respectively.
In today’s article, we’re going to talk about this naming structure, so that next time you admire the back of soup can, you won’t look so puzzled. We’ll also cover several common definitions that every novice biohacker should be familiar with as well.
[NightHawkInLight] wants what may be the impossible – a dirt cheap replacement for a laser cutter or a water jet. He’s got this crazy idea about using electrolysis to etch sheet steel parts, but he just can’t get the process to work. Sounds like a job for the Hackaday community.
In theory, electrolytic cutting of metal is pretty simple to understand. Anyone who lives in the northeast of the USA knows all about how road salt can cut holes in steel given enough time – say, one winter into payments on that new car. Adding a few electrons to the mix can accelerate the process of removing metal, but doing so in a controlled manner seems to be the crux of [NightHawkInLight]’s problem.
In his research into the method, he found a 2010 video by [InterestingProducts] of etching reed valves for DIY pulse jet engines from spring steel that makes it look easy. [NightHawkInLight] deviated from the reed valve process by substituting baking soda for salt to avoid the production of chlorine gas and changed up the masking technique by using different coatings. We applaud the empirical approach and hope he achieves his goal, but we tend to agree with frequent-Hackaday-tipline-project notable [AvE]’s assessment in the YouTube comments – the steel is just too darn thick. Once the etching starts, a third dimension is created at 90° to the surface and is then available to electrolyze, causing the corrosion to extend under the masking.
What does the Hackaday hive mind think? Is there any way to fix this process for thicker steel stock? Narrower traces, perhaps? Somehow modulating the current in the tank? Perhaps using the Hackaday logo would have helped? Chime in down below in the comments, and maybe we can all throw out our laser cutters.
Researchers recently observed negative refraction of electrons in graphene PN junctions. The creation of PN junctions in graphene is quite interesting, itself. Negative refraction isn’t a new idea. It was first proposed in 1968 and occurs when a wave bends–or refracts–the opposite way at an interface compared to what you would usually expect. In optics, for example, this can allow for refocusing divergent waves and has been the basis for some proposed invisibility cloaking devices.
In theory, negative refraction for electrons should be easy to observe at PN junctions, but in practice, the band gap voltage causes most electrons to reflect at the junction instead of refract. However, a graphene PN junction has no band gap voltage, so it should be ideal. However, previous attempts to find negative refraction in graphene were not successful.
Unless you’ve been living under a high voltage transformer, you’ve heard about the potential for Samsung’s latest phone, the Note7, to turn into a little pocket grenade without warning. With over 2.5 million devices in existence, it’s creating quite a headache for the company and its consumers.
They quickly tied the problem to faulty Li-ion batteries and started replacing them, while issuing a firmware update to stop charging at 60 percent capacity. But after 5 of the replacement phones caught fire, Samsung killed the Note7 completely. There is now a Total Recall on all Note7 phones and they are no longer for sale. If you have one, you are to turn it off immediately. And don’t even think about strapping it into a VR headset — Oculus no longer supports it. If needed, Samsung will even send you a fireproof box and safety gloves to return it.
Every airline has been broadcasting warnings not to power on or charge a Note 7 on a plane. Image Source: CNET
It should be noted that the problem only affects 0.01% of the phones out there, so they’re not exactly going to set the world on fire. However, it has generated yet another discussion about the safety of Li-ion battery technology.
It was just a few months ago we all heard about those hoverboards that would catch fire. Those questionably-engineered (and poorly-named) toys used Li-ion batteries as well, and they were the source of the fire problem. In the wake of this you would think all companies manufacturing products with Li-ion batteries in them would be extra careful. And Samsung is no upstart in the electronics industry — this should be a solved problem for them.
Why has this happened? What is the deal with Li-ion batteries? Join me after the break to answer these questions.
Every now and then you need to make your own capacitor. That includes choosing a dielectric for it, the insulating material that goes between the plates. One dielectric material that I use a lot is paraffin wax which can be found in art stores and is normally used for making candles. Another is resin, the easiest to find being automotive resin used for automotive body repairs.
The problem is that you sometimes need to do the calculations for the capacitor dimensions ahead of time, rather than just throwing something together. And that means you need to know the dielectric constant of the dielectric material. That’s something that the manufacturer of the paraffin wax that makes it for art stores won’t know, nor will the manufacturers of automotive body repair resin. The intended customers just don’t care.
It’s therefore left up to you to measure the dielectric constant yourself, and here I’ll talk about the method I use for doing that.
