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.

Ultra-Black Material, Sustainably Made From Wood

September 2, 2024 by Donald Papp 40 Comments

Researchers at the University of British Columbia leveraged an unusual discovery into ultra-black material made from wood. The deep, dark black is not the result of any sort of dye or surface coating; it’s structural change to the wood itself that causes it to swallow up at least 99% of incoming light.

One of a number of prototypes for watch faces and jewelry.

The discovery was partially accidental, as researchers happened upon it while looking at using high-energy plasma etching to machine the surface of wood in order to improve it’s water resistance. In the process of doing so, they discovered that with the right process applied to the right thickness and orientation of wood grain, the plasma treatment resulted in a surprisingly dark end result. Fresh from the plasma chamber, a wood sample has a thin coating of white powder that, once removed, reveals an ultra-black surface.

The resulting material has been dubbed Nxylon (the name comes from mashing together Nyx, the Greek goddess of darkness, with xylon the Greek word for wood) and has been prototyped into watch faces and jewelry. It’s made from natural materials, the treatment doesn’t create or involve nasty waste, and it’s an economical process. For more information, check out UBC’s press release.

You have probably heard about Vantablack (and how you can’t buy any) and artist Stuart Semple’s ongoing efforts at making ever-darker and accessible black paint. Blacker than black has applications in optical instruments and is a compelling thing in the art world. It’s also very unusual to see an ultra-black anything that isn’t the result of a pigment or surface coating.

VR Headset With HDMI Input Invites A New Kind Of Cyberdeck

September 1, 2024 by Donald Papp 30 Comments

Meta’s Quest VR headset recently got the ability to accept and display video over USB-C, and it’s started some gears turning in folks’ heads. [Ian Hamilton] put together a quick concept machine consisting of a Raspberry Pi 400 that uses a VR headset as its monitor, which sure seems like the bones of a new breed of cyberdeck.

With passthrough on, one still sees the outside world.

The computer-in-a-keyboard nature of the Pi 400 means that little more than a mouse and the VR headset are needed to get a functional computing environment. Well, that and some cables and adapters.

What’s compelling about this is that the VR headset is much more than just a glorified monitor. In the VR environment, the external video source (in this case, the Raspberry Pi) is displayed in a window just like any other application. Pass-through can also be turned on, so that the headset’s external cameras display one’s surroundings as background. This means there’s no loss of environmental awareness while using the rig.

[Note: the following has been updated for clarity and after some hands-on testing] Video over USB-C is technically DisplayPort altmode, and both the video source and the USB-C cable have to support it. In [Ian]’s case, the Raspberry Pi 400 outputs HDMI and he uses a Shadowcast 2 capture card to accept HDMI on one end and outputs video over USB-C on the other.

Here’s how it works: the Quest has a single USB-C port on the side, and an app (somewhat oddly named “Meta Quest HDMI link”) running on the headset takes care of accepting video over USB and displaying it in a window within the headset. The video signal expected is UVC (or USB Video Class), which is what most USB webcams and other video devices output. (There’s another way to do video over USB-C which is technically DisplayPort altmode, and both the video source and the USB-C cable have to support it. That is not what’s being used here; the Quest does not support this format. Neither is it accepting HDMI directly.) In [Ian]’s case, the Raspberry Pi 400 outputs HDMI and he uses a Shadowcast 2 capture card to accept HDMI on one end and output UVC video on the other, which is then fed into the Quest over a USB-C cable.

As a concept it’s an interesting one for sure. Perhaps we’ll see decks of this nature in our next cyberdeck contest?

Symmetrical Gear Spins One-Way, Harvesting Surrounding Chaos

August 30, 2024 by Donald Papp 12 Comments

Here’s a novel ratchet mechanism developed by researchers that demonstrates how a single object — in this case a gear shaped like a six-pointed star — can rectify the disordered energy of its environment into one-way motion.

5x speed video of gear in agitated water bath.

The Feynman–Smoluchowski ratchet has alternating surface treatments on the sides of its points, accomplished by applying a thin film layer to create alternating smooth/rough faces. This difference in surface wettability is used to turn agitation of surrounding water into a ratcheting action, or one-way spin.

This kind of mechanism is known as an active Brownian ratchet, but unlike other designs, this one doesn’t depend on the gear having asymmetrical geometry. Instead of an asymmetry in shape, there’s an asymmetry in the gear tooth surface treatments. You may be familiar with the terms hydrophobic and hydrophilic, which come down to a difference in surface wettability. The gear’s teeth having one side of each is what rectifies the chaotic agitation of the surrounding water into a one-way spin. Scaled down far enough, these could conceivably act as energy-harvesting micromotors.

Want more detail? The published paper is here, and if you think you might want to play with this idea yourself there are a few different ways to modify the surface wettability of an object. High voltage discharge (for example from a Tesla coil) can alter surface wettability, and there are off-the-shelf hydrophobic coatings we’ve seen used in art. We’ve even seen an unusual clock that relied on the effect.

What’s New In 3D Scanning? All-In-One Scanning Is Nice

August 27, 2024 by Donald Papp 29 Comments

3D scanning is important because the ability to digitize awkward or troublesome shapes from the real world can really hit the spot. One can reconstruct objects by drawing them up in CAD, but when there isn’t a right angle or a flat plane in sight, calipers and an eyeball just doesn’t cut it.

Scanning an object can create a digital copy, aid in reverse engineering, or help ensure a custom fit to something. The catch is making sure that scanning fits one’s needs, and isn’t more work than it’s worth.

I’ve previously written about what to expect from 3D scanning and how to work with it. Some things have changed and others have not, but 3D scanning’s possibilities remain only as good as the quality and ease of the scans themselves. Let’s see what’s new in this area.

All-in-One Handheld Scanning

MIRACO all-in-one 3D scanner by Revopoint uses a quad-camera IR structured light sensor to create 1:1 scale scans.

3D scanner manufacturer Revopoint offered to provide me with a test unit of a relatively new scanner, which I accepted since it offered a good way to see what has changed in this area.

The MIRACO is a self-contained handheld 3D scanner that, unlike most other hobby and prosumer options, has no need to be tethered to a computer. The computer is essentially embedded with the scanner as a single unit with a touchscreen. Scans can be previewed and processed right on the device.

Being completely un-tethered is useful in more ways than one. Most tethered scanners require bringing the object to the scanner, but a completely self-contained unit like the MIRACO makes it easier to bring the scanner to the subject. Scanning becomes more convenient and flexible, and because it processes scans on-board, one can review and adjust or re-scan right on the spot. This is more than just convenience. Taking good 3D scans is a skill, and rapid feedback makes practice and experimentation more accessible.

Continue reading “What’s New In 3D Scanning? All-In-One Scanning Is Nice” →

This Is Not A Laptop, It’s A KVM Combo

August 19, 2024 by Donald Papp 67 Comments

A spare monitor and keyboard are handy things to have around, but they’re a bit of a hassle. They are useful for hardware development, plugging in to headless servers, or firing up a Raspberry Pi or similar single-board computer (SBC). If that’s something you do and portability and storage space are important to you, then you may be interested in the CrowView Note.

I got an opportunity to test and provide feedback on an early version of this unusual device, which is functionally a portable spare monitor plus keyboard (and touchpad) without the bulk and extra cables. Heck, it’s even giving me ideas as the guts of a Cyberdeck build. Let’s take a look.

What It Is

It really looks like a laptop, but it’s actually a 14″ 1920 x 1280 monitor and USB keyboard in a laptop form factor.

There is also an integrated trackpad, speakers and mic, and a rechargeable battery. That makes it capable of providing its own power, and it can even function as a power bank in a pinch. There’s an HDMI input on one side, and on the other is a full-featured USB-C port that accepts video input via the DisplayPort altmode.

Pictured here is a Raspberry Pi 5 with optional PCB adapter to eliminate cables. The three ports (HDMI in, USB-C 5 V out, and USB-A for peripherals) provide all the board needs.

The CrowView Note is a pretty useful device for a workbench where one is often plugging hardware in for development or testing, because there’s no need to manage a separate monitor, keyboard, and mouse.

It is not a laptop, but attaching an SBC like a Raspberry Pi makes it act like one. The three ports conveniently located on the left-hand side (HDMI in, USB-C out for power to the SBC, and USB-A in for peripherals like keyboard and trackpad) are all that are needed in this case. Elecrow offers a “cable eliminator” PCB adapters to make the process of connecting a Raspberry Pi 5 or a Jetson Nano as simple as possible. The result is something that looks and works just like a laptop.

Well, almost. The SBC will still be a separate piece of hardware, whether connected by cables or by one of Elecrow’s PCB adapters. The result is OK for bench work, but especially in the case of the PCB adapter, not particularly rugged. Still, it’s a nice option and makes working on such boards convenient and cable-free.

Continue reading “This Is Not A Laptop, It’s A KVM Combo” →