Healing Wounds With The Power Of Electricity

May 4, 2022 by Zoe Skyforest 36 Comments

Once upon a time, even a simple cut or scrape could be a death sentence. Before germ theory and today’s scientific understanding of medicine, infections ran rampant and took many lives.

While we’re now well-armed with disinfectants, dressings, and antibiotics, scientists are continuing to investigate new and unique methods to improve the treatment of wounds. As it turns out, a little electricity might actually help wounds heal faster.

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A square PCB with a Raspberry Pi Pico mounted in the middle

Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer

May 3, 2022 by Robin Kearey 37 Comments

If you’re a radiation enthusiast, chances are you’ve got a Geiger counter lying around somewhere. While Geiger counters are useful to detect the amount of radiation present, and with a few tricks can also distinguish between the three types of radiation (alpha, beta and gamma), they are of limited use in identifying radioactive materials. For that you need a different instrument called a gamma-ray spectrometer.

Spectrometers are usually expensive and complex instruments aimed at radiation professionals. But it doesn’t have to be that way: physics enthusiast [NuclearPhoenix] has designed a hand-held gamma spectrometer that’s easy to assemble and should fit in a hobbyist budget. It outputs spectral plots that you can compare with reference data to identify specific elements.

A PCB with a sensor wrapped in black tape — The scintillator and sensor are wrapped in black tape to block out ambient light.

The heart of the device is a scintillation crystal such as thallium-doped sodium iodide which converts incoming gamma rays into visible light. The resulting flashes are detected by a silicon photomultiplier whose output is amplified and processed before being digitized by a Raspberry Pi Pico’s ADC. The Pico calculates the pulses’ spectrum and generates a plot that can be stored on its on-board flash or downloaded to a computer.

[NuclearPhoenix] wrote a convenient program to help analyze the output data and made all design files open-source. The hardest part to find will be the scintillation crystal, but they do pop up on auction sites like eBay now and then. We’ve featured an Arduino-based gamma spectrometer before; if you’ve always wanted to roll your own scintillators, you can do that too. Continue reading “Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer” →

The Deadliest Project On The Internet?

May 2, 2022 by Ryan Flowers 96 Comments

Before deciding whether the headline of this article is clickbait, please take a moment to watch the excellent video by [BigClive] below the break. And then, go to your local search engine and search the phrase “fractal burning death”. We’ll wait.

With that out of the way, we have to admit that when we saw the subject “The most deadly project on the Internet” on [bigclivedotcom]’s YouTube channel, we were a bit skeptical. It’s a big claim. But then we watched the video and did some googling. Sadly, there are over 30 documented cases of this project killing people, and more cases of permanent grievous injury.

The results of Fractal Wood Burning with High Voltage

Fractal Burning is a hobby where wood is burned by slathering wood in a conductive slurry and then applying high voltage to either side of the wood, usually using something not rated for high voltage, such as jumper cables. The High Voltage is supplied by an unmodified Microwave Oven Transformer. Other projects using MOT’s typically rip out the high voltage secondary windings and re-wind them as low voltage, high amperage transformers, and are using in Spot Welders and even arc welders.

As laid out by [BigClive], the voltages coming from an unmodified MOT, ranging from 2-3 KV (That’s between two and three thousand Volts) at a very low impedance are right up there in the “Don’t go near it!” territory.

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Hackaday Prize 2022: Glass Tube Solar Thermionic Converters

April 27, 2022 by Zoe Skyforest 13 Comments

Typically, if you want to convert solar energy into electrical energy, you use either photovoltaic (PV) cells, or you use the sunlight to create steam to turn a turbine. Both of these methods are well-established and used regularly in both small- and grid-scale applications. However, [Nick Poole] wanted to investigate an alternative method, using thermionic converters for solar power generation.

[Nick] has been gearing up to produce various styles of vacuum tubes, and noted that the thermionic effect that makes them work could also be used to generate electricity. They are highly inefficient and produce far less power than a photovoltaic solar cell, meaning they’re not in common use. However, as [Nick] notes, unlike PV cells etched in silicon, a thermionic converter can be built with basic glassworking tools, requiring little more than a torch, a vacuum pump, and a spot welder.

Experiments with a large lens to focus sunlight onto a 6V3A diode tube showed promise. [Nick] was able to generate half a volt, albeit at a tiny current, with the design not being optimized for thermionic conversion. Further experiments involved electrically heating a pair of diode tubes, which was able to just barely light an LED at 1.7 V and a current of 7.5 uA. The conversion efficiency was a lowly 0.00012%, around 5 orders of magnitude worse than a typical PV cell.

[Nick]’s hope is that he can produce a tube designed specifically to maximize thermionic conversion for energy generation purposes. It’s likely there is some low-hanging fruit in terms of gains to be made simply by optimizing the design for this purpose, even if the technique can’t compete with other solar generation methods.

In any case, we’re eager to see what [Nick] comes up with! We love to see makers building tubes in their own home workshops.

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2022 Sci-Fi Contest: Multi-Sensor Measurement System

April 26, 2022 by Zoe Skyforest 4 Comments

Many sci-fi movies and TV shows feature hand-held devices capable of sensing all manner of wonderful things. The µ Spec Mk II from [j] is built very much in that vein, packing plenty of functionality into a handy palm-sized form factor.

An ESP32 serves as the brains of the device, hooked up to a 480×320 resolution touchscreen display. On board is a thermal camera, with 32×24 pixel resolution from an MLX90640 sensor. There’s also a 8×8 LIDAR sensor, too, and a spectral sensor that can capture all manner of interesting information about incoming light sources. This can also be used to determine the transmission coefficient or reflection coefficient of materials, if that’s something you desire. A MEMS microphone is also onboard for capturing auditory data. As a bonus, it can draw a Mandelbrot set too, just for the fun of it.

Future plans involve adding an SD card so that data captured can be stored in CSV format, as well as expanding the sensor package onboard. It’s a project that reminds us of some of the tricorder builds we’ve seen over the years. Video after the break.

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Modern Wildfires And Their Effect On The Ozone Layer

April 26, 2022 by Zoe Skyforest 36 Comments

The ozone layer is a precious thing, helping protect the Earth from the harshest of the sun’s radiative output. If anything were to damage this layer, we’d all feel the results in a very short order indeed.

In the past, humanity has worked to limit damage to the ozone layer from our own intentional actions. However, it’s not just aerosol cans and damaged air conditioning systems that are putting it at risk these days. The fierce wildfires we’ve seen so much of in recent years are also having a negative effect. Let’s take a look at why the ozone layer matters, and how it’s being affected by these wildfires.

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Explosion Welding Goes Off With A Bang

April 25, 2022 by Zoe Skyforest 25 Comments

Welding is often a hot and noisy process. It generally involves some fancy chemistry and proper knowledge to achieve good results. Whether you’re talking about arc, TIG, or MIG, these statements all apply.

The same is true for explosion welding, though it’s entirely unlike any traditional hand welding methods you’ve ever seen before. Today, we’ll explore how this technique works and the applications it’s useful for. Fire in the hole!

Don’t Blow Them Apart, Blow Them Together!

Explosion welding occurs near-instantaneously, but is done in a progressive fashion. The angle of collision, as well as the speed of the explosive front, is key to getting a quality weld. Image credit: NASA, public domain

The technique of explosion welding is relatively new compared to other metal-joining techniques. In the two World Wars of the 20th century, pieces of shrapnel were often found stuck to armor plating. Close observation showed that shrapnel was in fact welding on to metal armor, rather than simply being embedded in such. Given that collisions between shrapnel and armor often occur without the extreme heat of typical welding operations, it indicated that it was instead great velocity of the impact between shrapnel and armor that was melding the metals together.

The same results were later recreated in the lab, and explosoin welding was developed into a refined technique after World War II. 1962 saw DuPont patent a process for explosion welding later to be known under the “Detaclad” trademark.

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