Let's make a Liquid Metal satellite thruster

I made a liquid metal field emission electric thruster. It nearly broke me 😅

🥰 CONSIDER SUBSCRIBING 🥰

[BreakingTaps]

So apparently Gallium/Indium is called "EGaln". I knew it wasn't technically galinstan since it doesn't have the tin, but couldn't find a proper name for it. Cheers to everyone for the note!

[mikeselectricstuff]

Plasmas can have negative resistance characteristics, which causes instability, which is why current limiting is needed for a stable discharge.

[JoeSmith-cywj]

And a week later all aluminum in shop crumbles

[mikeselectricstuff]

BTW for high-voltages, old-school solid carbon resistors work well - not really made nowadays but can be found as old stock. I used them on my 1MV Marx generator and they are pretty much indesctructable
The problem with most film resistors is they are typically a coated cylinder with a spiral slot cut in it, so the creepage distance isn't very long. The thin film is also rather fragile and easily damaged by spark discharges.

[Argosh]

I appreciated you writing that vacuum didn't work either. It's enjoyable to be taken serious as an audience 😉

[michaelkalin]

i love watching someone else suffer through a project for a change. makes me feel a bit more sane. great job on this one.

[Ionee-qf]

this channel is so great, sometimes we are looking close at metal, sometimes we are watching a cool milling process, sometimes we are making an ion engine. Love your work.

[Hexum]

Zach is slowly becoming the Dude. :)
Another great vid! Thank you.

[calcs]

I have to say I laughed out load and said “vacuum?” and then you flashed the black screen saying no vacuum did t work, lol 😂

It was almost too perfect

[jaymchari]

Please don't push yourself too much. Thank you for your videos.

[kellen_mcsmellin]

I would imagine that the reason your 1M current limiting resistors were getting burnt up was that when the arcs occur, you're essentially putting the full 10kV across the 1M resistor, causing about 100W of of power going into the little 2-3W resistor. Increasing the resistance to 50-100M would solve this problem (and it sounds like that's what you ended up doing!)

[esra_erimez]

Why don't rockets get sad? They always have a blast.

[wanglydiaplt]

Get hold of a guy named Jerg Jergensen in Santa Barbara, CA. Ages ago he used to make ion sources for Hughes and he knows a lot about your predicament. :-)

[SolarMillUSA]

@5:20 just a thought about the issue of breaking down the oxide film that immediately forms. This sounds like a very similar issue to what happens with aluminum. In welding we use AC voltage and adjust the percentage time balance between the electrode positive and negative. We want electronegative most of the time because it puts more heat into the part, but we use around 30% electropositive which creates a cleaning effect on the aluminum and breaks down the oxide. I’m wondering if you could do something similar here with the gallium. Obviously you would need to bond it to the negative side of the circuit initially, but maybe you could create an ignition circuit that is similar to a pilot arc that starts with cleaning the metal and gradually transitions entirely to DC as an active surface is achieved. If you’ve already thought of this to my apologies for saying the obvious. (I work in product research, design, and development and by consequence also end up doing a lot of fabrication work).

[WildEngineering]

hey some EE tips, the resistors arent dying because of voltage, the voltage rating on a resistor is to make sure it doesnt arc across the windings. Your resistor was burning up because it was too low wattage. Get a 10W sized resistor.

[Nuovoswiss]

Two thoughts: first, instead of just current-limiting resistors, how about pairing those with current-limiting inductors? Nothing prevents sudden jumps in current like inductors. Second, you could try pre-saturating (or supersaturating) gallium with hydrogen, so that instead of forming surface oxides, it will just produce surface water, which will evaporate in vacuum. One method of hydrogen supersaturation in other fields was using the metal as the cathode in a water electrolysis cell, where they could achieve hydrogen equivalent pressures in the mega-bar range; though those were with solid metals, so with liquid gallium you might just end up with gallium soda... but maybe just a bit of ambient-pressure hydrogen doping would be sufficient to reduce oxide skin formation.

[thesciencefurry]

12:51 "The enginerring department here at breaking tabs is full on ADHD"

Procrastinating the entire time and doing things in a panic right at the last minute? lol

[Danny.._]

you should call up the slow-mo guys to film some of this stuff!

[LanceThumping]

Congratulations on your success with the project.
I am incredibly jealous of you and others on YT that can work on all these interesting projects.

[load]

IT'S SO CUTE!

Sir, I worked a wafer fab for a brief bit as a repair & maintenance intern in thin films & you remain an inspiration.

Same reaction I had to seeing oxygen have a color for the first time. (:

I replicated the LIGraphene after I saw your video on it because you made it seem so approachable. Tried to make a finger capacitor on 6" wide roll of polyamide but couldn't get the power supply to power it appropriately. Never figured out the root cause & it drove me up the wall.

Just know your work is inspiring & I'm grateful to see your latest project.