High Voltage Gives Metal Balls A Mind Of Their Own

May 25, 2021 by Tom Nardi 19 Comments

Have you ever seen something that’s so fascinating you’re sure there has to be some kind of practical application for it, but you just can’t figure out what? That’s how we feel when watching tiny ball bearings assemble themselves into alien-like structures under the influence of high voltage in the latest Plasma Channel video from [Jay Bowles].

Now to be clear, [Jay] isn’t trying to take credit for the idea. He explains that researchers at Stanford University first documented the phenomenon back in 2015, and that his goal was to recreate their initial results as a baseline and go from there. The process is pretty simple: put small metal ball bearings into a tray of oil, apply high voltage, and watch them self-assemble into “wires” that branch out in search of the ground terminal like a plant’s roots looking for water. With the encouragement of his 500,000 volt Van de Graaff generator, the ball bearings leaped into action and created structures just like in the Stanford study.

With the basic pieces now in place, [Jay] starts to push the envelope. He experiments with various oils to see how their viscosity impacts the ball’s ability to assemble, finding that olive oil seems to be the ideal candidate (at least of those he’s tried so far). He also switches up the size and shape of the tray, to try and find how far the balls can realistically stretch out on their own.

In the end we’re no closer to finding a practical application for this wild effect than the good folks at Stanford were back in 2015, but at least we got to watch the little fellows do their thing in glorious 4K and with the exceptional production value we’ve come to expect from Plasma Channel. That said, [Jay] does hint at his ongoing efforts to turn the structures into works of art by “freezing” them with clear resin, so keep your eyes out for that.

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Supersized Van De Graaff Generator Packs A Punch

April 27, 2021 by Tom Nardi 19 Comments

The Van de Graaff generator is a staple of science museums, to the point that even if the average person might not know its name, there’s an excellent chance they’ll be familiar with the “metal ball that makes your hair stand up” description. That’s partly because they’re a fairly safe way to show off high voltages, but also because they’re surprisingly cheap and easy to build.

In his latest Plasma Channel video [Jay Bowles] builds a large Van de Graaff generator that wouldn’t look out of place in a museum or university, which he estimates is producing up to 500,000 volts. It can easily throw impressive looking (and sounding) sparks 10 inches or more, and as you can see in the video below, is more than capable of pulling off those classic science museum tricks.

It’s really quite amazing to see just how little it takes to generate these kinds of voltages with a Van de Graaff. In fact there’s nothing inside that you’d immediately equate with high voltage, the only electronic component in the generator’s base beyond the battery pack is a motor speed controller. While everything else might look suspiciously like magic, our own [Steven Dufresne] wrote up a properly scientific explanation of how it all works.

In this particular case, the motor spins a nylon pulley in the base of the generator, which is connected to a Teflon pulley in the top by way of a neoprene rubber belt. Combs made from fine metal mesh placed close to the belt at the top and bottom allow the Van de Graaff to build up a static charge in the sphere. Incidentally, it sounds like sourcing the large metal sphere was the most difficult part of this whole build, as it took [Jay] several hours to modify the garden gazing ball to fit atop the acrylic tube that serves as the machine’s core.

In the past we’ve seen Van de Graaff generators built out of literal trash, and back in 2018, [Jay] himself put together a much smaller and more simplistic take on the concept. But this beauty certainly raises the bar beyond anything we’ve seen previously.

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