A Compact Electrohydrodynamic Pump Using Copper And TPU

June 9, 2024 by 21 Comments

Electrohydrodynamics (EHD) involves the dynamics of electrically charged fluids, which effectively means making fluids move using nothing but electric fields, making it an attractive idea for creating a pump out of. This is the topic of a 2023 paper by [Michael Smith] and colleagues in Science, titled “Fiber pumps for wearable fluidic systems”. The ‘fiber pumps’ as they call the EHD pumps in this study are manufactured by twisting two helical, 80 µm thick copper electrodes around a central mandrel, along with TPU (thermoplastic polyurethane) before applying heat. This creates a tube where the two continuous electrodes are in contact with any fluids inside the tube.

For the fluid a dielectric fluid is required to create the ions, which was 3M Novec 7100, a methoxy-fluorocarbon. Because of the used voltage of 8 kV, a high electrical breakdown of the fluid is required. After ionization the required current is relatively low, with power usage reported as 0.9 W/m, with one meter of this pump generating a pressure of up to 100 kilopascals and a flowrate of 55 mL/minute. One major limitation is still that after 6 days of continuous pumping, the copper electrodes are rendered inert due to deposits, requiring the entire system to be rinsed. Among the applications the researchers see artificial muscles and flexible tubing in clothing to cool, heat and provide sensory feedback in VR applications.

While the lack of moving parts as with traditional pumps is nice, the limitations are still pretty severe. What is however interesting about this manufacturing method is that it is available to just about any hobbyist who happens to have some copper wiring, TPU filament and something that could serve as a mandrel lying around.

Thanks to [Aaron Eiche] for the tip.

What If The Matrix Was Made In The 1950s?

June 9, 2024 by 30 Comments

We’ve noticed a recent YouTube trend of producing trailers for shows and movies as if they were produced in the 1950s, even when they weren’t. The results are impressive and, as you might expect, leverage AI generation tools. While we enjoy watching them, we were especially interested in [Patrick Gibney’s] peek behind the curtain of how he makes them, as you can see below. If you want to see an example of the result first, check out the second video, showing a 1950s-era The Matrix.

Of course, you could do some of it yourself, but if you want the full AI experience, [Patrick] suggests using ChatGPT to produce a script, though he admits that if he did that, he would tweak the results. Other AI tools create the pictures used and the announcer-style narration. Another tool produces cinematographic shots that include the motion of the “actors” and other things in the scene. More tools create the background music.

Continue reading “What If The Matrix Was Made In The 1950s?” →

Oral-B Hopes You Didn’t Use Your $230 Alexa-Enabled Toothbrush

June 8, 2024 by 31 Comments

With companies desperate to keep adding more and more seemingly random features to their products, Oral-B made the logical decision to add Alexa integration to its Oral-B Guide electric toothbrush. Taking it one step beyond just Bluetooth in the toothbrush part, the Guide’s charging base also acted as an Alexa-enabled smart speaker, finally adding the bathroom to the modern, all-connected smart home. Naturally Oral-B killed off the required Oral-B Connect smartphone app earlier this year, leaving Guide owners stranded in the wilderness without any directions. Some of the basics of this shutdown are covered in a recent Ars Technica article.

Amidst the outrage, it’s perhaps good to take a bit more of a nuanced view, as despite various claims, Oral-B did not brick the toothbrush. What owners of this originally USD$230 device are losing is the ability to set up the charging base as an Alexa smart speaker, while the toothbrush is effectively just an Oral-B Genius-series toothbrush with Bluetooth and associated Oral-B app. If you still want to have a waterproof smart speaker listening in while in the bathroom, you’ll have to look elsewhere, it seems. Meanwhile existing customers can contact Oral-B support for assistance, while the lucky few who still have the Connect app installed better hope it doesn’t disconnect, as reconnecting it to the smart speaker seems to be impossible, likely due to services shut down by Oral-B together with the old “oralbconnect.com” domain name.

We recently looked at a WiFi-enabled toothbrush as well, which just shows how far manufacturers of these devices are prepared to go, whether they intend to support it in any meaningful fashion or not.

Embrace IPv6 Before Its Too Late?

June 8, 2024 by 96 Comments

Many hackers have familiar sayings in their heads, such as “If it ain’t broke, don’t fix it” and KISS (Keep it simple, stupid). Those of us who have been in the field for some time have habits that are hard to break. When it comes to personal networks, simplicity is key, and the idea of transitioning from IPv4 to IPv6 addresses seems crazy. However, with the increasing number of ‘smart’ devices, streaming media gadgets, and personal phones, finding IPv4 space for our IoT experiments is becoming difficult. Is it time to consider embracing IPv6?

The linked GitHub Gist by [timothyham] summarizes the essential concepts for home network admins to understand before making changes. The first major point is that IPv6 has a vastly larger address space than IPv4, eliminating the need to find spare IPv4 addresses. IPv6 assigns multiple addresses to the same interface. The 128-bit addresses are split into a 64-bit prefix assigned by your ISP and a 64-bit interface identifier. Using SLAAC (Stateless Address Autoconfiguration), clients can manage their own addresses. You don’t have to use SLAAC, but it will make life easier. The suffix typically remains static, allowing integration with a local DNS server.

Continue reading “Embrace IPv6 Before Its Too Late?” →

Screwless Eyeballs Are A Lesson In Design-For-Assembly

June 8, 2024 by 9 Comments

[Will Cogley] makes eyeballs; hey, everyone needs a hobby, and we don’t judge. Like all his animatronics, his eyeballs are wondrous mechanisms, but they do tend toward being a bit complex, especially in terms of the fasteners needed to assemble them.

But not anymore. [Will] redid his eyeball design to be as easy to assemble as possible, and the results are both impressive and instructive. His original design mimics real eyeballs quite well, but takes six servos and a large handful of screws and nuts, which serve both to attach the servos to the frame and act as pivots for the many, many linkages needed. The new design has snap-fit pivots similar to Lego Technic axles printed right into the linkage elements, as well as snap connectors to hold the servos down. This eliminates the need for 45 screws and cuts assembly time from 30 minutes to about six, with no tools required. And although [Will] doesn’t mention it, it must save a bunch of weight, too.

Everything comes at a cost, of course, and such huge gains in assembly ease are no exception. [Will] details this in the video below, including printing the parts in the right orientation to handle the forces exerted both during assembly and in use. And while it’s hard to beat a five-fold reduction in assembly time, he might be able to reduce that even more with a few print-in-place pivots.

Continue reading “Screwless Eyeballs Are A Lesson In Design-For-Assembly” →

A screenshot of the website, showing various parts from Western manufacturers

How Many Western ICs Are There In Russia’s Weapons?

June 8, 2024 by 60 Comments

Recently, the Ukrainian government has published a database of Western components being used in recently produced Russian armaments, and it’s a fascinating scroll. Just how much does Russia rely on Western manufacturers’ parts? It turns out, a surprising amount. For instance, if you are wondering which ICs are used to build Iran-produced Shahed drones, it seems that it’s a whole bunch of Texas Instruments parts, as well as some Maxim, Intel, and Xilinx ones. Many of the parts in the lists are MCUs and FPGAs, but it’s also surprising how many of the components are jelly bean parts with multiple suppliers.

There appear to be thousands of parts listings, compiled from a good few dozen pieces of equipment that volunteers appear to have taken apart and scrupulously documented – just take a look at the dropdowns at the top of the page. The Ukrainian government is advocating for parts restrictions to be implemented based upon this data – as we all remember, it’s way harder to produce hardware when you can’t buy crucial ICs.

Even for a regular hacker, this database is worth a scroll, if only to marvel at all the regular parts we wouldn’t quite associate with military use. Now, all that’s left is to see whether any of the specific chips pictured have been sold to washing machine manufacturers.

Gas-Tight FDM 3D Printing Is Within Your Grasp

June 8, 2024 by 65 Comments

The widespread availability of inexpensive 3D printers has brought about a revolution in what can be easily made at home. However these creations aren’t perfect, particularly when it comes to the adhesion between their layers. Aside from structural failures along the layer lines there is also the question of those joins being permeable, limiting the possibility for waterproof or gas proof prints. It’s something [German Engineer] has tackled in a new video, in which he’s looking at the design and preparation of small propane tanks.

A blurry image of a red 3d-printed part exploding
This is the frame at which the 3D printed tank explodes

The attraction of propane as a fuel is that it liquefies easily on compression, so a propane cylinder or tank will be an equilibrium of liquid propane with pressurized gas above it, whose pressure depends on the ambient temperature. This means that any tank must be expected to have a working pressure somewhere between 150 and 200 PSI, with of course a design pressure far exceeding that for safety reasons.

Filling a 3D printed tank immediately results in the propane escaping, as he demonstrates by putting one of his prints under water. He solves this with a sealant, Diamant Dichtol, which is intended to polymerize in the gaps between layers and create a gas-tight tank. A range of three tanks of different thicknesses are treated this way, and while the 1 mm thick variety bursts, the thicker ones survive.

It’s clear that this technique successfully creates gas-tight prints, and we can see the attraction of a small and lightweight fuel tank. But we can’t help worrying slightly about the safety, for even when the material is a lightweight 3D print, high pressure equipment is not to be trifled with. Tanks do burst, and when that happens anyone unfortunate enough to be close by sustains nasty, even life-threatening injuries. Use the technique, but maybe don’t hit it with high pressures.

Continue reading “Gas-Tight FDM 3D Printing Is Within Your Grasp” →