Ultrasonic soldering is a little-known technology that allows soldering together a variety of metals and ceramics that would not normally be possible. It requires a special ultrasonic soldering iron and solder that is not cheap or easy to get hold of, so [Ben Krasnow] of [Applied Science] made his own.
Ultrasonic soldering irons heat up like standard irons, but also require an ultrasonic transducer to create bonds to certain surfaces. [Ben] built one by silver soldering a piece of stainless steel rod (as a heat break) between the element of a standard iron and a transducer from an ultrasonic cleaner. He made his special active solder by melting all the ingredients in his vacuum induction furnace. It is similar to lead-free solder, but also contains titanium and small amounts of cerium and gallium. In the video below [Ben] goes into the working details of the technology and does some practical experimentation with various materials.
Ultrasonic soldering is used mainly for electrically bonding metals where clamping is not possible or convenient. The results are also not as neat and clean as with standard solder. We covered another DIY ultrasonic soldering iron before, but it doesn’t look like that one ever did any soldering.
Ultrasonic energy has several interesting mechanical applications that we’ve covered in the past, including ultrasonic cutting and ultrasonic welding.
For most of human history, there was no such thing as a professional scientist. Those who dabbled in “natural philosophy” were mainly men — and occasionally women — of privilege and means, given to spend their time looking into the workings of the world. Most went where their interest lay, exploring this facet of geology or that aspect of astronomy, often combining disciplines or switching to new ones as they felt like it. They had the freedom to explore the universe without the pressure to “publish or perish,” and yet they still often managed to pull back the curtain of ignorance and superstition that veiled the world for eons, at least somewhat.
In their footsteps follow today’s citizen scientists, a relatively small cohort compared to the great numbers of professional scientists that universities churn out year after year. But where these credentialed practitioners are often hyper-focused on a particular sub-field in a highly specialized discipline, the citizen scientist enjoys more freedom to explore the universe, as his or her natural philosopher forebears did. These citizen scientists — many of whom are also traditionally credentialed — are doing important work, and some are even publishing their findings in mainstream journals. Continue reading “Citizen Science Hack Chat With Ben Krasnow”→
Join editors Elliot Williams and Mike Szczys as they unpack all the great hacks we’ve seen this week. On this episode we’re talking about laser Internet delivered from space, unwrapping the complexity of Charlieplexed circuits, and decapping ICs both to learn more about them and to do it safely at home. We have some fun with backyard siege weapons (for learning about physics, we swear!), gambling on FPGAs, and a line-scanning camera that’s making selfies fun again. And nobody thought manufacturing electroluminescent displays was easy, but who knew it was this hard?
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
The jet of pure water emerges from a 0.004″, or 100 micron, diameter sapphire orifice with a flow rate of around 2 milliliters per second giving a speed of 240 meters per second. It collides at 90° with a dielectric material where the plasma is produced as a toroid surrounding the collision point.
There’s been very little research into the phenomena but a proposal from one research paper which [Ben] found is that the plasma is a result of charging due to the triboelectric effect. This is the same effect which charges a balloon when you rub it against your hair, except that here there are water molecules running across a clear dielectric such as fused quartz. This effect results in a positively charged anode downstream of the collision while the water near the point of highest shear becomes conductive and conducts negative charge to the point of smallest curvature, producing a cathode. The electric field at the small-radius cathode acts like a short point with a high voltage on it, ionizing the air and forming the plasma. If this form of ionization sounds familiar, that’s because we’ve talked it occurring between the sharp wire and rounded foil skirt of a flying lifter.
[Ben] found support for the triboelectric theory when he substituted oil for the water. This didn’t produce any plasma, which is be expected since unlike water, oil is a non-polar molecule. However, while the researchers tried just a few dielectric materials, [Ben] had success with every transparent dielectric which he tried, including fused quartz, lithium niobate, glass, polycarbonate, and acrylic, some of which are very triboelectrically different from each other. So there’s room here for more theorizing. But check out his full video showing his equipment for producing the waterjet as well as his demonstrations and explanation.
After starting out with a demo of the firmware in action before and after his modification, he explains how the E-paper works. The display is made up of many isolated chambers, each containing charged particles in a liquid. For example, the positive particles might be black and the negative might be white. By putting an electric field across each chamber, the white particles would be attracted to one end while the black would be attracted to the other, which could be the end you’re looking at. He also explains how it’s possible to get a third color by using different sized particles along with some extra manipulation of the electric field. And he talks about the issue of burn-in and how to avoid it.
Having given us that background, he then walks us through some of the firmware and shows how he modified it to make it faster, namely by researching various datasheets and subsequently modifying some look-up-tables.
Turning back to the hardware, he shows how he scratches out some traces so that he can attach scope probes. This alone seems like a notable achievement, though he points out that the conductive layer holds up well to his scratching. At that point he analyses the signals while running some demos.
The result is the very informative, interesting and entertaining video which you can watch below.
Ben Krasnow is a consummate prototyper. He’s built a machine that makes the perfect chocolate chip cookie, he has a ruby laser, and he produces his own liquid nitrogen in-house because simply filling up a dewar is too easy. If you need a prototype, Ben is the guy to talk to.
Ben gave a talk at last year’s Hackaday Superconference on prototyping quickly and verifying technical hypotheses. The philosophy can be summed up simply as, ‘Build First, and Ask Questions Later’. This philosophy served him well when he wanted to see if backscatter x-ray machines were actually more effective than metal detectors at TSA checkpoints. The usual bean-counter protocol for answering this question would be to find an x-ray expert, wait weeks, pay tens of thousands of dollars, and eventually get an answer. Ben simply built his own backscatter x-ray machine from parts sourced on eBay.
After the talk, we asked Ben about the limits of this philosophy of building first and asking questions later. With the physical and mental toolset Ben has, it’s actually easy to build something that can get in the ballpark of answering a question. The problem comes when Ben needs to prove something won’t work.
Answering this question is all a matter of mindset. In Ben’s view, if a prototype works, a hypothesis is verified. Even if it’s a complete accident, he’s totally okay with the results. Some of his other colleagues have an opposite mindset — if a quick and dirty prototype doesn’t work, a research hypothesis is verified.
This rapid-proof-of-concept mindset is something we see a lot in the Hackaday audience, and we know there are some of you out there who have a mind and garage that is at least as impressive as Ben’s. We’ve extended the Call for Proposals for the 2017 Hackaday Superconference. If you have a story about rapid prototyping or just making the perfect chocolate chip cookie with robots, we want to hear about it. Tickets are still available for the Superconference in Pasadena, California on November 11th and 12th.