Chemistry And Lasers Turn Any Plastic Surface Into A PCB

September 4, 2018 by Dan Maloney 30 Comments

On the face of it, PCB production seems to pretty much have been reduced to practice. Hobbyists have been etching their own boards forever, and the custom PCB fabrication market is rich with vendors whose capabilities span the gamut from dead simple one-side through-hole boards to the finest pitch multilayer SMD boards imaginable.

So why on Earth would we need yet another way to make PCBs? Because as [Ben Krasnow] points out, the ability to turn almost any plastic surface into a PCB can be really handy, and is not necessarily something the fab houses handle right now. The video below shows how [Ben] came up with his method, which went down a non-obvious path that was part chemistry experiment, part materials science. The basic idea is to use electroless copper plating, a method of depositing copper onto a substrate without using electrolysis.

This allows non-conductive substrates — [Ben] used small parts printed with a Formlabs SLA printer — to be plated with enough copper to form solderable traces. The chemistry involved in this is not trivial; there are catalysts and surfactants and saturated solutions of copper sulfate to manage. And even once he dialed that in, he had to figure out how to make traces and vias with a laser cutter. It was eventually successful, but it took a lot of work. Check out the video below to see how he got there, and where he plans to go next.

You’ve got to hand it to [Ben]; when he decides to explore something, he goes all in. We appreciate his dedication, whether he’s using candles to explore magnetohydrodynamics or making plasma with a high-speed jet of water.

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Non-Newtonian Batteries

September 2, 2018 by Brian McEvoy 43 Comments

Batteries placed in harm’s way need to be protected. A battery placed where a breakdown could endanger a life needs to be protected. Lithium-ion batteries on the bottoms of electric cars are subject to accidental damage and they are bathed in flame-retardant epoxy inside a metal sled. Phone batteries are hidden behind something that will shatter or snap before the battery suffers and warrant inspection. Hoverboard batteries are placed behind cheap plastic, and we have all seen how well that works. Batteries contain chemicals with a high density of energy, so the less exploding they do, the better.

Researchers at Oak Ridge National Laboratory have added a new ingredient to batteries that makes them armored but from the inside. The ingredient is silica spheres so fine it is safe to call it powder. The effect of this dust is that the electrolyte in every battery will harden like cornstarch/water then go right back to being a liquid. This non-Newtonian fluid works on the ~~principal~~ principle of shear-thickening which, in this case, says that the suspension will become harder as shear force is applied. So, batteries get rock hard when struck, then go back to being batteries when it is safe.

Non-Newtonian fluids are much fun, but we’re also happy to see them put to use. The same principle works in special speed bumps to allow safe drivers to continue driving but jolts speeders. Micromachines can swim in non-Newtonian fluids better than water in some cases.

See The Fabulous Workmanship In This Smart Pressure Regulator

August 28, 2018 by Donald Papp 8 Comments

For many projects that require control of air pressure, the usual option is to hook up a pump, maybe with a motor controller to turn it on and off, and work with that. If one’s requirements can’t be filled by that level of equipment and control, then it’s time to look at commercial regulators. [Craig Watson] did exactly that, but found the results as disappointing as they were expensive. He found that commercial offerings — especially at low pressures — tended to leak air, occasionally reported incorrect pressures, and in general just weren’t very precise. Out of a sense of necessity he set out to design his own electronically controlled, closed-loop pressure regulator. The metal block is a custom manifold with valve hardware mounted onto it, and the PCB mounted on top holds the control system. The project logs have some great pictures and details of the prototyping and fabrication process.

This project was the result of [Craig]’s work on a microfluidics control system, conceived because he discovered that much of the equipment involved in these useful systems is prohibitively expensive for small labs or individuals. In the course of developing the electronic pressure regulator, he realized it could have applications beyond microfluidics control, and created it as a modular device that can easily be integrated into other systems and handle either positive or negative pressure. It’s especially well-suited for anything with low air requirements and a limited supply, but with a need for precise control.

[Cody] Builds A Chlorine Machine

August 19, 2018 by Dan Maloney 51 Comments

In his continuing bid to have his YouTube channel demonetized, [Cody] has decided to share how he makes chlorine gas in his lab. Because nothing could go wrong with something that uses five pounds of liquid mercury and electricity to make chlorine, hydrogen, and lye.

We’ll be the first to admit that we don’t fully understand how the Chlorine Machine works. The electrochemistry end of it is pretty straightforward – it uses electrolysis to liberate the chlorine from a brine solution. One side of the electrochemical cell generates chlorine, and one side gives off hydrogen as a byproduct. We even get the purpose of the mercury cathode, which captures the sodium metal as an amalgam. What baffles us is how [Cody] is pumping the five pounds of mercury between the two halves of the cell. Moving such a dense liquid would seem challenging, and after toying with more traditional approaches like a peristaltic pump, [Cody] leveraged the conductivity of mercury to pump it using a couple of neodymium magnets. He doesn’t really explain the idea other than describing it as a “rail-gun for mercury,” but it appears to work well enough to gently circulate the mercury. Check out the video below for the build, which was able to produce enough chlorine to dissolve gold and to bleach cloth.

We need to offer the usual warnings about how playing with corrosive, reactive, and toxic materials is probably not for everyone. His past videos, from turning urine into gunpowder to mining platinum from the side of the road, show that [Cody] is clearly very knowledgeable in the ways of chemistry and that he takes to proper precautions. So if you’ve got a jug of mercury and you want to try this out, just be careful.

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Reverse Engineering A DNA Sequencer

August 9, 2018 by Tom Nardi 19 Comments

Improvements in methodology have dramatically dropped the cost of DNA sequencing in the last decade. In 2007, it cost around $10 million dollars to sequence a single genome. Today, there are services which will do it for as little as $1,000. That’s not to bad if you just want to examine your own DNA, but prohibitively expensive if you’re looking to experiment with DNA in the home lab. You can buy your own desktop sequencer and cut out the middleman, but they cost in the neighborhood of $50,000. A bit outside of the experimenter’s budget unless you’re Tony Stark.

But thanks to the incredible work of [Alexander Sokolov], the intrepid hacker may one day be able to put a DNA sequencer in their lab for the cost of a decent oscilloscope. The breakthrough came as the result of those two classic hacker pastimes: reverse engineering and dumpster diving. He realized that the heavy lifting in a desktop genome sequencer was being done in a sensor matrix that the manufacturer considers disposable. After finding a source of trashed sensors to experiment with, he was able to figure out not only how to read them, but revitalize them so he could introduce a new sample.

To start with, [Alexander] had to figure out how these “disposable” sensors worked. He knew they were similar in principle to a digital camera’s CCD sensor; but rather than having cells which respond to light, they read changes in pH level. The chip contains 10 million of these pH cells, and each one needs to be read individually hundreds of times to capture the entire DNA sequence.

Enlisting the help of some friends who had experience reverse engineering silicon, and armed with an X-Ray machine and suitable optical microscope, he eventually figured out how the sensor matrix worked electrically. He then designed a board that reads the sensor and dumps the “picture” of the DNA sample to his computer over serial.

Once he could reliably read the sensor, the next phase of the project was finding a way to wash the old sample out so it could be reloaded. [Alexander] tried different methods, and after several wash and read cycles, he nailed down the process of rejuvenating the sensor so its performance essentially matches that of a new one. He’s currently working on the next generation of his reader hardware, and we’re very interested to see where the project goes.

This isn’t the first piece of DIY DNA hardware we’ve seen here at Hackaday, and it certainly won’t be the last. Like it or not, hackers are officially fiddling with genomes.

The “P Cell” Is Exactly What You Might Suspect

August 6, 2018 by Donald Papp 34 Comments

[Josh Starnes] had a dream. A dream of a device that could easily and naturally be activated to generate power in an emergency, or just for the heck of it. That device takes in urea, which is present in urine, and uses it to generate a useful electrical charge. [Josh] has, of course, named this device the P Cell.

An early proof of concept uses urine to create a basic galvanic cell with zinc and copper electrodes, but [Josh] has other ideas for creating a useful amount of electricity with such a readily-available substance. For example, the urea could be used to feed bacteria or micro algae in a more elegantly organized system. Right now the P Cell isn’t much more than a basic design, but the possibilities are more than just high-minded concepts. After all, [Josh] has already prototyped a Hybrid Microbial Fuel Cell which uses a harmonious arrangement of bacteria and phytoplankton to generate power.

[Josh]’s entries were certainly among some of the more intriguing ones we saw in the Power Harvesting Challenge portion of The Hackaday Prize, and we’re delighted that his ideas will be in the running for the Grand Prize of $50,000.

Cheap PSoC Enables Electrochemistry Research

August 4, 2018 by Dan Maloney 8 Comments

You may think electrochemistry sounds like an esoteric field where lab-coated scientists labor away over sophisticated instruments and publish papers that only other electrochemists could love. And you’d be right, but only partially, because electrochemistry touches almost everything in modern life. For proof of that look no further than your nearest pocket, assuming that’s where you keep your smartphone and the electrochemical cell that powers it.

Electrochemistry is the study of the electrical properties of chemical reactions and does indeed need sophisticated instrumentation. That doesn’t mean the instruments have to break the grant budget, though, as [Kyle Lopin] shows with this dead-simple potentiostat built with one chip and one capacitor. A potentiostat controls the voltage on an electrode in an electrochemical cell. Such cells have three electrodes — a working electrode, a reference electrode, and a counter electrode. The flow of electrons between these electrodes and through the solutions under study reveal important properties about the reduction and oxidation states of the reaction. Rather than connect his cell to an expensive potentiostat, [Kyle] used a Cypress programmable system-on-chip development board to do everything. All that’s needed is to plug the PSoC into a USB port for programming, connect the electrodes to GPIO pins, and optionally add a 100 nF capacitor to improve the onboard DAC’s accuracy. The video below covers the whole process, albeit with a barely audible voiceover.

Still not sure about electrochemistry? Check out this 2018 Hackaday Prize entry that uses the electrochemistry of life to bring cell phones back to life.

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