Using Ultrasound And Microbubbles To Make Tiny Devices

October 20, 2026 by 9 Comments

Although we generally do not look at bubbles in fluids as more than a curiosity – if not an outright annoyance – in certain contexts they can be very useful. If you can namely control their formation and position, you can use them in small systems to control actuators and dynamically affect acoustic systems. The main issues here are that controlling their formation, lifetime and controllability remain hard to solve. This is what [Zhiyuan Zhang] et al. sought to address, with a recent study published in Science Advances covering their approach using ultrasound-driven, electronically programmable microbubbles.

There’s also a Cornell press release article about their findings, which uses a new device that produces hydrogen bubbles along a grid of electrodes, before using ultrasound to steer them around. Using this chip-like device they claim to be able to control the 10-100 micron sized bubbles, with the ultrasound matching the resonant frequency of the target bubble. With each bubble size having its own resonant frequency, this allows for individual control by varying the induced oscillations.

Although in the demonstrated 2D setup this microbubble approach works well, it still requires a fairly bulky bench top setup around it which would need to be scaled down to be more practical. There is also the issue that the chamber geometry affects the movement of a bubble, which becomes especially important to further research when using complex (3D) chambers with this technology.

Lazarus And The Free Pascal Compiler Gain Dynamic Package Support

October 20, 2026 by 21 Comments

"Built with Free Pascal Lazarus" bannerIf you have developed in Pascal or Delphi in the past decades, you’re probably familiar with the Lazarus IDE that provides an interface to the Free Pascal Compiler (FPC), much like Delphi’s IDE. For users of Lazarus IDE there’s now an exciting new development, with the announcement that FPC and Lazarus now support dynamic packages.

The upshot of this is that you no longer need to rebuild the IDE if you want to add components, controls and Lazarus extensions. In addition you can use this same dynamic package feature in your own Pascal applications this way.

Naturally this is a great improvement, and it’s good to see more improvements to such a venerable programming language. Not only is it still being used today for just about anything, including web development, but there is a good case to be made for using Pascal today as it’s no longer the language it was half a decade ago.

We’d also be remiss to not mention the legacy of [Niklaus Wirth], who not only created Pascal, but was also instrumental in the development of Object Pascal together with Apple. This effort ultimately led to everything from Turbo Pascal to Delphi, FPC and so much more, making it a heartening sight to see this legacy being kept alive today.

Going Whole-Hog On A First Satellite Ground Station

October 20, 2026 by 10 Comments

When most radio enthusiasts start trying to pick up signals from satellites, they might put together a quick-and-dirty Yagi antenna and try to catch a repeater as is passes overhead, or they might grab a small unused dish from a satellite TV service and point it up at a weather satellite by hand to try to decode some of the data coming down. But [Cranktown City] had a different approach. He found an eight-foot dish online and built a massive articulating base station out of it as his first exploration into the world of satellites.

The first problem that needs to be solved with a dish of this size is its mounting location. This installation uses a large post and concrete foundation with a custom-fabricated metal base at the bottom. The metal base houses all of the electronics not just for receiving signals from the dish, but also for orienting it properly. That includes a large metal gear driven by a wheelchair motor to control its azimuth and a linear actuator to take care of its elevation. Getting the large dish onto the frame was its own ordeal, complicated by the fact that it’s not uniform in its shape and has to be mounted in a specific orientation.

With everything assembled, the circularly-polarized antenna installed, and the computers up and running, the dish is able to track satellites across the sky and download data from things like GOES weather satellites. [Cranktown City] also built in a system that detects wind and points the dish vertically when it goes above a certain speed. This level of effort is impressive, and absolutely not required to listen in on plenty of sattelite activity out in the sky, but this installation will certainly give [Cranktown City] a lot of mileage and possibly even work for some radio astronomy.

Continue reading “Going Whole-Hog On A First Satellite Ground Station” →

NASA’s Lunar Grounding Challenge Is A Real Buzz

October 20, 2026 by 25 Comments

One could make a joke about how an astronaut walking on the lunar surface is rather akin to a cat walking on the carpet in the living room, but out in space the resulting triboelectric discharge can do a lot more damage than just some stinging fingers and a bemused looking cat.

The problem that NASA and other space agencies are dealing with is that the charge that builds up on a lunar-walking astronaut is very hard to equalize with something like a lunar lander. For this reason they have now set up the Lunar Grounding Challenge to consult the public whilst dangling $150,000 of rewards in front of anyone ready to pounce with a good idea.

Here on Earth we have many ways in which we can get rid of unwanted charge: dry winter weather, for instance, demonstrates effectively that humidity is a crucial factor here. With no real atmosphere on the Moon, each astronaut becomes a walking capacitor, which is worsened when said astronaut ventures outside of the sunlit areas and then returns to the slightly positively charged lander.

The challenge here is to equalize the astronaut and lander, with a design specification of a -100 kV or higher astronaut and about 100 V lander. A resulting current should not exceed 1 mA, ideally less than 0.2 mA to remain below human perception levels. If an arc exists it should not contact the suit or astronaut.

Of course, the most low-tech solution would be to use a resistor to limit the current, but at those voltage ranges it would take an awful long time to bleed off, in an environment that’s basically a perfect insulator. It definitely seems like a fun challenge to sink one’s fangs into.

A series of ten close up images of two pieces of coral. In the first, on the top left, the coral on the left is bright white while the one on the right is brown with darker brown spots. Text reads: "Week 0." The last image, on the bottom right, shows both pieces of coral as brown with darker brown spots and the text, "Week 9." The intervening images show the white, dead coral, slowly becoming more brown as time progresses.

Spreading Life To Bleached Coral

October 20, 2026 by 16 Comments

Coral bleaching is a major problem for ocean ecosystems as the ocean gets warmer. Researchers at Stanford have found a new method for regenerating bleached corals.

Scientists working on coral found that when they had a bleached and healthy example accidentally touching in the lab, the symbionts from the healthy coral that make its food were able to spread to the bleached coral, reviving it in a matter of weeks. Contact was only required for one week, although three days was sufficient in a few cases. The effect only seems to work with corals of the same genet as the healthy corals of other genets just take over the bleached coral antagonistically.

This is particularly exciting, as areas where not all coral has bleached may indicate the presence of symbionts that are more heat tolerant, and being able to spread these symbionts to their neighbors quickly can greatly speed up the process of coral regeneration and save the reef. Coral reefs are some of the most vibrant ecosystems in the ocean, so if you save the coral, you can save many other species as well that rely on them.

If you’d like to explore how the coral is doing near you, perhaps you should try an open ROV or a bionic jellyfish?

Super Mario Galaxy Now Runs On The GBA

October 20, 2026 by 2 Comments

Joining the ranks of fresh backported Nintendo games is Super Mario Galaxy for the Nintendo Game Boy Advance (GBA), courtesy of [Tobias Friedly], AKA [Tobi]. In a recent video he announces the release of this game, along with the release of the source code of the engine and all the game’s code in a GitHub project.

Naturally none of the original Wii game’s assets are provided to appease Nintendo’s vicious lawyers, so you’re expected to bring your own super-legally acquired ISO image or equivalent to fill in these blanks when you build your ROM for the GBA.

This is a mostly complete port, even integrating the star pointer despite the GBA’s limited number of controls compared to the Wii. In some situations it’s opted to have star bits automatically collected to work around this limitation, which is probably a quality-of-life improvement that many SMG players will appreciate.

For the game’s logic a lot of code was borrowed from the recently decompiled version of the original game, which saved a lot of time even if the GBA’s hardware is no match for the Wii’s. From the gameplay in the video it definitely looks like a playable version of the game, with an acceptable frame rate that looks to be worth a try.

Continue reading “Super Mario Galaxy Now Runs On The GBA” →

Visualize Regular Expressions With Marbles

October 20, 2026 by 15 Comments

If you are one of those people who visualize things physically better than in the abstract, then Regex Marble Run by [bottomless] might be for you. You enter a test expression and a string, and the site generates a virtual marble machine that lets you see the regular expression pick apart the string in a physical way.

Click this link, and you’ll see the regular expression “^[hH]ack.[dD][^0-9]*$” which, if you aren’t a regular expression user, might seem a bit cryptic. However, it is fairly simple if you take it bit-by-bit.

The caret character tells it to match the start of the string. So “^dog” will match “dog” and “dog food” but won’t match “food for a dog.” The following bit “[hH]” will match either “h” or “H”. Then there is “ack” which is just what you think it is. So a string starting with “hack” or “Hack” might match (depending on the rest of the expression.

The period means match any single character. Then there’s another “[]” but this time with “dD” to match any kind of D. The next “[]” character class is a range from 0-9, but since there is a caret, the match is negated. So “[^0-9]” means match anything except a digit from 0 to 9. The “*” means we can have zero or more of these. So “HackxD” matches, but so does “HackxDXYZabc” for now. Trick question: Does “HackxDXYZabc123” match? So far, yes, but it only matches to the lowercase “c” character.

The final character, “$” means end of string. So now “HackxDXYZabc123” does not match because we are still in the middle of the string. However, “HackxDXYZabc” will match since the previous “*” “ate” the rest of the string.

Head spinning? The site will let you see each letter of a test string as a marble that falls through the different parts of the regular expression. Balls that pass wind up in the left-hand box, while failures are in the right-hand box. Will it help you? We don’t know, but it is fun to watch.

Want a refresher on regular expressions? Or perhaps you want some practice?