Fail Of The Week: A Potentially Lethal Tattoo Removal Laser Power Supply

March 24, 2024 by Dan Maloney 7 Comments

Caveat emptor is good advice in general, but in the wilds of eBay, being careful with what you buy could be life-saving. To wit, we present [Les Wright]’s teardown and very ginger power-up of an eBay tattoo-removal laser power supply.

Given that [Les] spent all of around $100 on this widowmaker, we’re pretty sure he knew what he was getting himself into. But he likely wasn’t quite prepared for the scale of the sketchiness this thing would exhibit. The deficiencies are almost too many to number, starting with the enclosure, which is not only made completely of plastic but assembled from individual sheets of flat plastic stock that show signs of being glued together by hand. Even the cooling water tank inside the case is pieced together this way, which probably led to the leaks that corroded the PCBs. Another assembly gem is the pair of screws the big energy storage capacitor is jammed under, presumably to hold it in place — because nothing says quality like a BOM that can’t spring for a couple of cable ties. Click through the break to read more and see the video.

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How Tattoos Interact With The Immune System Could Have Impacts For Vaccines

April 5, 2023 by Lewin Day 41 Comments

Tattoos are an interesting technology. They’re a way of marking patterns and designs on the skin that can last for years or decades. All this, despite the fact that our skin sloughs off on a regular basis!

As it turns out, tattoos actually have a deep and complex interaction with our immune system, which hold some of the secrets regarding their longevity. New research has unveiled more insight into how the body responds when we get inked up.

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I See By Your Tattoo That You Are A Hacker

November 28, 2022 by Anne Ogborn 38 Comments

We spotted [Segfault]’s new tattoo on a fast failing bird app a few days ago. We thought it was nice looking piece of skin art, but without a write up couldn’t cover it. The bearer of the tattoo pointed us to this blog post about the tattoo, and now we really like it.

It’s fun on it’s own, but when you start staring at it you realize it’s full of hidden jokes and meanings. If you like puzzles, go hunting for them before you read the blog post. We also liked the reminiscence about [Segfault]’s early electronics experimentation days, and how the 555 timer IC figured prominently in them.

We’ve not covered a lot of tattoos here at Hackaday. Mostly we cover the technology behind skin fused or embedded hacks. But occasionally some tattoo art catches our eye, as it did in this interesting barcode tattoo.

Tracking Vaccination History With Invisible Tattoos

January 3, 2020 by Sharon Lin 57 Comments

Nowadays, we still rely on medical records to tell when our last vaccinations were. For social workers in developing countries, it’s an incredibly difficult task especially if there isn’t a good standard in place for tracking vaccinations already.

A team at the Massachusetts Institute of Technology may be providing a solution – they’ve developed a safe ink to be embedded into the skin alongside the vaccine, only visible under a special light provided by a smartphone camera app. It’s an inconspicuous way to document the patient’s vaccination history directly into their skin and low-risk enough to massively simplify the process of maintaining medical records for vaccines.

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Laser Welding With A Tattoo Removal Gun

December 25, 2019 by Lewin Day 49 Comments

Dating as far back as the early 1960’s, researchers were zapping tattoo inks with laser light was an effective way to remove the markings from human skin. At the time it was prohibitively expensive. But the desire to have an undo-button for badge choices is strong, and thus the tattoo removal gun was born.

These days you can pick up one of these zappy, burn-y wonders for far less than a flagship cellphone put their high-power-output to alternative use. [Andrew] recently discovered that these devices can be readily repurposed into a laser welding tool with just a bit of work under the hood.

He first came across the technology via videos from [styropyro], whose work we’ve featured before. The tattoo removal gun features a YAG laser, which is pulsed to create a high power density. In initial testing, the pulses were too short and of too high intensity to effectively weld with; instead, the pulses simply cratered the metal.

After delving in further, [Andrew] discovered that by removing the Q-switch optical component, the pulses from the laser could be lengthened. This reduces the power density, and allows the tool to weld various materials even on its lower power settings. Success was found welding steel, titanium, and other materials, though attempts to weld copper and silver faced little success. Test pieces included razor blades and small screws, which could easily be welded with the tool. Results of the razor blade welding is spectacular, with a high-quality welding bead achieved by taping the laser to a CNC mill for precise movement.

It could prove to be a useful tool for those experimenting with complex projects involving bonding metals at very fine scales. If you’re pursuing something exotic yourself, we want to hear about it!

Imitating Art In Life With A Reverse-Engineered Tattoo

March 23, 2019 by Dan Maloney 6 Comments

In general, tattoo artists are not electrical engineers. That’s fine; the world needs both professions. But when you need a circuit designed, you’re better off turning to an EE rather than a tattoo artist. And you certainly don’t want an EE doing your new ink. Disaster lies that way.

Surprisingly, [Missa]’s tattoo of a heart-shaped circuit turned out at least to be plausible design, even if it’s not clear what it’s supposed to do. So her friend [Jeremy Elson] took up the challenge to create a circuit that looked like the tattoo while actually doing something useful. He had to work around the results of tattoo artistic license, like sending traces off to the board’s edge and stranding surface-mount components without any traces. The artist had rendered an 8-pin DIP device, albeit somewhat proportionally challenged, so [Jeremy] went with an ATtiny85, threw on a couple of SMD resistors and a cap, and placed two LEDs for the necessary blinkenlights. Most of the SMDs are fed from traces on the back of the board that resurface through vias, and a small coin cell hidden on the back powers it. One LED blinks “Happy Birthday [Missa]” in Morse, while the other blinks prime numbers from 2 to 23 – we’ll assume this means it was [Missa]’s 23rd birthday.

There’s a surprising amount of crossover between the worlds of electronics and tattooing. We’ve featured functional temporary tattoo circuits, prison-expedient tattoo guns, and even a CNC tattoo machine.

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Tech Tattoos Trace Two Dimensions

January 5, 2019 by Brian McEvoy 7 Comments

Flexible circuit boards bend as you might expect from a playing card, while skin stretches more like knit fabric. The rules for making circuit boards and temporary tattoos therefore need to be different. Not just temporary tattoos, there are also circuits that reside on the skin so no unregulated heat traces, please. In addition to flexing and stretching, these tattoos can be applied to uneven surfaces and remain intact. Circuits could be added to the outside of projects or use the structure as the board to reduce weight and size. Both are possible with the research from Carnegie Mellon’s Soft Machines Lab and the Institute of Systems and Robotics at the University of Coimbra.

These circuits are an improvement over the existing method which relies on cropping away metal foil with a magnifying glass, tweezers and a steady hand. Instead, silver particles are printed with an inkjet printer before the traces are coated in eutectic gallium indium which is liquid metal at room temperature. If we were to oversimplify, we might describe it as similar to a non-toxic equivalent of mercury that we have also seen used in DIY OLEDs. This is a development likely to be interesting in a range of fields from medicine to cosplay.

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