If you’ve ever sloshed coffee out of your mug and watched the tiny particles scurry to the edges of the puddle, then you’ve witnessed a genuine mystery of fluid mechanics called the coffee ring effect. The same phenomenon happens with spilled wine, and with functional inks like graphene.
Graphene and other 2D crystals print much better under the influence of alcohol.
The coffee ring effect makes it difficult to print graphene and similar materials onto silicon wafers, plastics, and other hard surfaces because of this drying problem. There are already a few commercial options that can be used to combat the coffee ring effect, but they’re all polymers and surfactants that negatively affect the electronic properties of graphene.
Some cool-mist humidifiers work by flinging water at a vaporizer, but our favorite kind uses a piezoelectric transducer. These work by using high-frequency sound waves to pound the surface of the water with mechanical energy. That energy introduces standing waves that force the water to break apart into a fine mist on the surface of the piezo disk.
The driving circuit for this DIY mist maker uses a 555 to generate 113 KHz, a trimmer potentiometer to fine-tune it, and a MOSFET to amplify the signal. You don’t need much more than that and a handful of passives to recreate this cool junk box experiment, but the spec of the piezo disk is quite important. The circuit is designed for atomizing transducers, which have a resonant frequency of 113 KHz — much higher than your average junk box piezo. Check out the demo and build video after the break.
Keyboard key stabilizers, or stabs as they’re known in enthusiast circles, do exactly what you’d expect — they stabilize longer keys like the Shifts and the space bar so that they don’t have to be struck dead-center to actuate evenly. Stabs work by flanking the key switch with two non-functional switch actuators linked with a thick wire bar. Some people love stabs and insist on stabilizing every key that’s bigger than 1u, while other people think stabs are more trouble than they’re worth for various reasons, like rattling.
Although the print is an easy one, [Riskable] says the design process wasn’t as cut and dried as it seems. The center points of the stabilizer stems aren’t supposed to be in the center of cutouts, even though it looks that way to the naked eye. After that, the pain point has shifted to the wire, and getting it as straight as possible before making the necessary bends. [Riskable] is going to make a straightener to help out, and we suggest something like this one.
It’s true what they say — you never know what you can do until you try. Russell Kirsch, who developed the first digital image scanner and subsequently invented the pixel, was a firm believer in this axiom. And if Russell had never tried to get a picture of his three-month-old son into a computer back in 1957, you might be reading Hackaday in print right now. Russell’s work laid the foundation for the algorithms and storage methods that make digital imaging what it is today.
Russell reads SEAC’s last printout. Image via TechSpot
Russell A. Kirsch was born June 20, 1929 in New York City, the son of Russian and Hungarian immigrants. He got quite an education, beginning at Bronx High School of Science. Then he earned a bachelor’s of Electrical Engineering at NYU, a Master of Science from Harvard, and attended American University and MIT.
In 1951, Russell went to work for the National Bureau of Standards, now known as the National Institutes of Science and Technology (NIST). He spent nearly 50 years at NIST, and started out by working with one of the first programmable computers in America known as SEAC (Standards Eastern Automatic Computer). This room-sized computer built in 1950 was developed as an interim solution for the Census Bureau to do research (PDF).
Standards Eastern Automatic Computer (SEAC) was the first programmable computer in the United States. Credit: NIST via Wikimedia
Like the other computers of its time, SEAC spoke the language of punch cards, mercury memory, and wire storage. Russell Kirsch and his team were tasked with finding a way to feed pictorial data into the machine without any prior processing. Since the computer was supposed to be temporary, its use wasn’t as tightly controlled as other computers. Although it ran 24/7 and got plenty of use, SEAC was more accessible than other computers, which allowed time for bleeding edge experimentation. NIST ended up keeping SEAC around for the next thirteen years, until 1963.
The Original Pixel Pusher
This photo of Russell’s son Walden is the first digitized image. Public Domain via Wikimedia
The term ‘pixel’ is a shortened portmanteau of picture element. Technically speaking, pixels are the unit of length for digital imaging. Pixels are building blocks for anything that can be displayed on a computer screen, so they’re kind of the first addressable blinkenlights.
As the drum slowly rotated, a photo-multiplier moved back and forth, scanning the image through a square viewing hole in the wall of a box. The tube digitized the picture by transmitting ones and zeros to SEAC that described what it saw through the square viewing hole — 1 for white, and 0 for black. The digital image of Walden is 76 x 76 pixels, which was the maximum allowed by SEAC.
In in the video below, Russell discusses the idea and proves that variable pixels make a better image with more information than square pixels do, and with significantly fewer pixels overall. It takes some finagling, as pixel pairs of triangles and rectangles must be carefully chosen, rotated, and mixed together to best represent the image, but the image quality is definitely worth the effort. Following that is a video of Russell discussing SEAC’s hardware.
Russell retired from NIST in 2001 and moved to Portland, Oregon. As of 2012, he could be found in the occasional coffeehouse, discussing technology with anyone he could engage. Unfortunately, Russell developed Alzheimer’s and died from complications on August 11, 2020. He was 91 years old.
We would be preaching to the choir if we told you that fear is the action killer when it comes to the challenge of new projects in uncharted territory. Everyone who reads Hackaday knows that it takes mettle to forge through the self-doubt as we push ourselves to new engineering heights.
[JBV Creative] hears the voice, too: the one that says you can’t build that thing, it’s too difficult/useless. He knows that both creativity and anti-creativity stem from the same source — the powerful human mind that dreams up these projects in the first place.
The Encouragement Machine combines the two in a piece that engineers art from garbage, aka negative thoughts. It works by first acknowledging the most basal of discouraging thoughts — an important step of the process — and then it simply trims away the negativity.
This machine uses a stepper motor to feed receipt paper underneath a custom stamp that says YOU CAN’T DO IT. Then it passes the paper through a pair of servo-driven scissors that snip off the apostrophe-t.
Ironically or not, [JBV Creative] ran into a few issues with this build, but managed to muster up enough moxie to work through the problems without encouraging slips of paper. We have to wonder how much more smoothly the next project will go given all the positivity he now has on-demand.
[JBV] doesn’t delve into the electronics much, but it looks like an Arduino and a motor driver to us. We totally dig the design — it looks like an electrical substation or rocket launch pad that happens to have a Ferris wheel. Step right up and check out the build video after the break.
I guess it shouldn’t surprise me that by researching weird and interesting keyboards, I would uncover more weird and interesting keyboards. This is the BAT personal keyboard by Infogrip, and it’s something I came across while researching the DataHand keyboard and mentally filed away as something cool to look into.
When I came across a used BAT for a reasonable price, I snagged it, even though it didn’t come with any of the manuals or software, not even a cord. Like I said, reasonable price. I looked these keyboards up and found out that you can buy them new for a lot more than what I paid.
My gently used BAT in all its angular glory.The lowercase letter chords use either the middle thumb key or no thumb key. Image via Infogrip
Instead of stretching your fingers all over a regular keyboard, poking keys one at a time to spell out words, you press combinations of keys simultaneously, like playing chords on a piano.
You’re meant to use your thumb for the red, grey, and blue keys, and lay the other four on the rest of the keys. All of the alphabet keys are chorded with or without the gray thumb key, and all the number, symbol, and modifier keys are accessed through the red and blue layers.
Why would you want one of these? Well, given enough time to learn the chords, you can do anything a standard 104+ keyboard can do with only seven keys. You would never need to look down, not even for those weird seldom-used keys, and the only finger that ever travels is your thumb. All of this reduced hand/finger/wrist travel is going to be easier on the body.
The BAT lets you CAD like a madlad. Via Bill Buxton
The BAT is also part programmable macro pad, and from what I can gather, the main selling point was that you could quickly input shortcuts in CAD programs and the like, because you could keep one hand on the mouse.
The BAT came in both left- and right-handed versions that can be used either alone or together. Imagine how fast you could type if you chorded everything and split the typing duties between both hands! The only trouble is learning all those different finger combinations, although they say it doesn’t take that long.
Hit up the lighting aisle of any big box hardware store these days and you’ll probably find a variety of Edison bulbs — modern bulbs meant to evoke the bare, complicated tungsten filament bulbs from the early days of electric candlelight. Edison bulbs use filament LEDs, which resemble skinny candles with wicks at both ends and give off a nice light, especially when diffused by acrylic.
Our favorite part of the build elevates this simple light box into a curiosity for those not in the know. It’s controlled with a mercury tilt switch, so all you’d have to do in a power outage is locate the box and turn it upside down, provided it has a charge.
