Robotic Touch Using A DIY Squishy Magnetic Pad

September 22, 2024 by Donald Papp 5 Comments

There are a number of ways to give a robotic actuator a sense of touch, but the AnySkin project aims to make it an overall more reliable and practical process. The idea is twofold: create modular grippy “skins” that can be slipped onto actuators, and separate the sensing electronics from the skins themselves. The whole system ends up being quite small, as shown here.

Cast skins can be installed onto bases as easily as slipping a phone case onto a phone.

The skins are cast in whatever shape is called for by using silicone (using an off-the-shelf formulation from Smooth-on) mixed with iron particles. This skin is then slipped onto a base that contains the electronics, but first it is magnetized with a pulse magnetizer. It’s the magnetic field that is at the heart of how the system works.

The base contains five MLX90393 triple-axis magnetometers, each capable of sensing tiny changes in magnetic fields. When the magnetized skin over the base is deformed — no matter how slightly — its magnetic field changes in distinct ways that paint an impressively detailed picture of exactly what is happening at the sensor. As a bonus, slippage of the skin against the sensor (a kind of shearing) can also be distinctly detected with a high degree of accuracy.

The result is a durable and swappable robotic skin that can be cast in whatever shape is needed, itself contains no electronics, and can even be changed without needing to re-calibrate everything. Cameras can also sense touch with a high degree of accuracy, but camera-based sensors put constraints on the size and shape of the end result.

AnySkin builds on another project called ReSkin and in fact uses the same sensor PCB (design files and bill of materials available here) but provides a streamlined process to create swappable skins, and has pre-made models for a variety of different robot arms.

Jumperless Breadboard V5 Readies For Launch

September 21, 2024 by Donald Papp 10 Comments

When are jumper wires on a breadboard entirely optional? When it’s the latest version of [Kevin Santo Cappuccio]’s Jumperless, which uses a bunch of analog crosspoint switches (typically used for handling things like video signals) to create connections instead of physical wires. There’s even an RGB LED under each hole capable of real-time visualization of signals between components.

If this looks a bit familiar, that’s because an earlier version took second place in the 2023 Hackaday Prize. But things have evolved considerably since then. There are multiple programmable power rails, ADC channels, a rotary encoder, and much more. The PCB design itself is fantastic, including the probe which acts like a multi-function tool for interacting with the whole thing. The newest version will make its debut on Crowd Supply in just a few days.

It’s open source and made to be hackable, so give the GitHub repository a look if you want a closer peek. You can watch it in action in a brief video posted to social media, embedded below.

Continue reading “Jumperless Breadboard V5 Readies For Launch” →

An Espresso Machine For The DIY Crowd

September 15, 2024 by Donald Papp 29 Comments

Want to build your own espresso machine, complete with open-source software to drive it? The diyPresso might be right up your alley.

diyPresso parts, laid out and ready for assembly.

It might not be the cheapest road to obtaining an espresso machine, but it’s probably the most economical way to turn high-quality components (including a custom-designed boiler) and sensors into a machine of a proven design.

Coffee and the machines that turn it into a delicious beverage are fertile ground for the type of folk who like to measure, modify, and optimize. We’ve seen DIY roasters, grinders, and even a manual lever espresso machine. There are also many efforts at modifying existing machines with improved software-driven controls but this is the first time we’ve seen such a focused effort at bringing the DIY angle to a ground-up espresso machine specifically offered as a kit.

Curious to know more? Browse the assembly manual or take a peek at the software’s GitHub repository. You might feel some ideas start to flow for your next coffee hack.

Watch NASA’s Solar Sail Reflect Brightly In The Night Sky

September 15, 2024 by Donald Papp 14 Comments

NASA’s ACS3 (Advanced Composite Solar Sail System) is currently fully deployed in low Earth orbit, and stargazers can spot it if they know what to look for. It’s actually one of the brightest things in the night sky. When the conditions are right, anyway.

What conditions are those? Orientation, mostly. ACS3 is currently tumbling across the sky while NASA takes measurements about how it acts and moves. Once that’s done, the spacecraft will be stabilized. For now, it means that visibility depends on the ACS’s orientation relative to someone on the ground. At it’s brightest, it appears as bright as Sirius, the brightest star in the night sky.

ACS3 is part of NASA’s analysis and testing of solar sail technology for use in future missions. Solar sails represent a way of using reflected photons (from sunlight, but also possibly from a giant laser) for propulsion.

This perhaps doesn’t have much in the way of raw energy compared to traditional thrusters, but offers low cost and high efficiency (not to mention considerably lower complexity and weight) compared to propellant-based solutions. That makes it very worth investigating. Solar sail technology aims to send a probe to Alpha Centauri within the next twenty years.

Want to try to spot ACS3 with your own eyes? There’s a NASA app that can alert you to sighting opportunities in your local time and region, and even guide you toward the right region of the sky to look. Check it out!

Shedding New Light On The Voynich Manuscript With Multispectral Imaging

September 10, 2024 by Donald Papp 14 Comments

The Voynich Manuscript is a medieval codex written in an unknown alphabet and is replete with fantastic illustrations as unusual and bizarre as they are esoteric. It has captured interest for hundreds of years, and expert [Lisa Fagin Davis] shared interesting results from using multispectral imaging on some pages of this highly unusual document.

We should make it clear up front that the imaging results have not yielded a decryption key (nor a secret map or anything of the sort) but the detailed write-up and freely-downloadable imaging results are fascinating reading for anyone interested in either the manuscript itself, or just how exactly multispectral imaging is applied to rare documents. Modern imaging techniques might get leveraged into things like authenticating sealed packs of Pokémon cards, but that’s not all it can do.

Because multispectral imaging involves things outside our normal perception, the results require careful analysis rather than intuitive interpretation. Here is one example: multispectral imaging may yield faded text visible “between the lines” of other text and invite leaping to conclusions about hidden or erased content. But the faded text could be the result of show-through (content from the opposite side of the page is being picked up) or an offset (when a page picks up ink and pigment from its opposing page after being closed for centuries.)

[Lisa] provides a highly detailed analysis of specific pages, and explains the kind of historical context and evidence this approach yields. Make some time to give it a read if you’re at all interested, we promise it’s worth your while.

Spiders Are Somehow Hacking Fireflies To Lure More Victims

September 2, 2024 by Donald Papp 27 Comments

What happens when an unfortunate bug ends up in a spider’s web? It gets bitten and wrapped in silk, and becomes a meal. But if the web belongs to an orb-weaver and the bug is a male firefly, it seems the trapped firefly — once bitten — ends up imitating a female’s flash pattern and luring other males to their doom.

Fireflies communicate with flash patterns (something you can experiment with yourself using nothing more than a green LED) and males looking to mate will fly around flashing a multi-pulse pattern with their two light-emitting lanterns. Females will tend to remain in one place and flash single-pulse patterns on their one lantern.

When a male spots a female, they swoop in to mate. Spiders have somehow figured out a way to actively take advantage of this, not just inserting themselves into the process but actively and masterfully manipulating male fireflies, causing them to behave in a way they would normally never do. All with the purpose of subverting firefly behavior for their own benefit.

It all started with an observation that almost all fireflies in webs were male, and careful investigation revealed it’s not just some odd coincidence. When spiders are not present, the male fireflies don’t act any differently. When a spider is present and detects a male firefly, the spider wraps and bites the firefly differently than other insects. It’s unknown exactly what happens, but this somehow results in the male firefly imitating a female’s flash patterns. Males see this and swoop in to mate, but with a rather different outcome than expected.

The research paper contains added details but it’s clear that there is more going on in this process than meets the eye. Spiders are already fascinating creatures (we’ve seen an amazing eye-tracking experiment on jumping spiders) and it’s remarkable to see this sort of bio-hacking going on under our very noses.

The Strangest Way To Stick PLA To Glass? With A Laser And A Bit Of Foil

September 2, 2024 by Donald Papp 7 Comments

Ever needed a strong yet adhesive-free way to really stick PLA to glass? Neither have we, but nevertheless there’s a way to use aluminum foil and an IR fiber laser to get a solid bond with a little laser welding between the dissimilar materials.

A piece of sacrificial aluminum foil bonds the PLA to glass with a form of laser welding, with precise control and very little heat to dissipate.

It turns out that aluminum can be joined to glass by using a pulsed laser process, and PLA can be joined to aluminum with a continuous wave laser process. Researchers put them together, and managed to reliably do both at once with a single industrial laser.

By putting a sacrificial sheet of thin aluminum foil between 3D printed PLA and glass, then sending the laser through the glass into the aluminum, researchers were able to bond it all together in an adhesive-free manner with precise control, and very little heat to dissipate. No surface treatment of any kind required. The bond is at least as strong as any adhesive-based solution, so there’s no compromising on strength.

When it comes to fabrication, having to apply and manage adhesives is one of the least-preferable options for sticking two things together, so there’s value in the idea of something like this.

Still, it’s certainly a niche application and we’ll likely stick to good old superglue, but we honestly didn’t know laser welding could bond aluminum to glass or to PLA, let along both at once like this.