[youtube=http://www.youtube.com/watch?v=gMuDudCiPR8]
firstly, we don’t know why they are doing this, and we don’t care. You are watching an LED panel, controlled by molten metal. The panel has the leads sticking down below the bottom of the board, so the metal can make connections as it flows past. They are using Wood’s metal, not mercury so it has to be heated to about 159 degrees Fahrenheit to be fluid. This has been representing problems as the metal tends to stick to whatever container he is holding it in. That actually seems to be what most of the writeup and discussion are about, rather than, what it will be used for.
[Thanks Andre]
According to the linked Wikipedia article, Wood’s metal is quite toxic, especially when molten. Including the fumes…
Yes, we knew it was very toxic. No, we didn’t eat it.
Ha! Replacing mercury with Wood’s metal is the stupidest thing i’ve heard today. He goes on about how mercury is ‘far too toxic for my tastes’ – did he not consider the toxicity of the cadmium vapours? What about the lead too? What a numpty.
Yeah…….conceivably couldn’t any conductive liquid (ie just about anything not oil based) work? I mean I don’t know what the power source is, but using just the woods metal and a lubricant seems unnecessary.
According to wikipedia, field’s metal is a non-toxic alternative to wood’s metal.
http://en.wikipedia.org/wiki/Field%27s_metal
what if you just tossed some rosin flux in?
this definitely is an interesting project
I’m not sure the rosin flux would work at that temperature.
Good lord, cadmium and lead considered less toxic than mercury. For something as simple as this, saline would suffice.
Yep, you’d be better off with Field’s metal rather than Wood’s. Slightly lower melting point (only 3deg C though), less toxic, and a bit less wetting. If you can afford Cerrolow, that would work even better.
Awesome. Works in the same way that a mercury switch in an old thermostat does.
There are some Indium/Gallium/etc alloys that are significantly liquid down to about 10 C. Expensive, though, with Indium being about the price of silver, and Gallium being more than that. The alloys are considered non-toxic; they’ve replaced mercury in medical thermometers, for instance. Also, they tend to wet (stick to) everything, exactly UNLIKE mercury.
http://www.indium.com/products/fusiblealloys.php
I would have wired the leds using darlinton transistors or small fets and use the fluid to bias the base/gate. the devices are so sensitive that I’m sure you could get saline to set them off, you should even be able to get fade effects as their connection’s conductivity changes.
my project blinded me with science…
poisoned me with science
neutered me with science
Good luck with that.
john r for the win!
salt water? _genius!_
poisonous liquid metals? _less so._
gallium would work better, no? melts at 37c and is non toxic. expensive tho..
Hey, at least it’s not mercury. No gloves necessary, right?!
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Here is an idea dude is using a paper plate in the video so it can’t be a metal that has to have that much heat applied to it or it will melt straight through the bottom. With that I would still bet on it being mercury or like these guys said the new replacements for it out of some old salvaged medical blood pressure equipment.
Awesome. Works in the same way that a mercury switch in an old thermostat does.
Posted at 3:12 pm on Feb 16th, 2009 by Christopher Reitmann
There are some Indium/Gallium/etc alloys that are significantly liquid down to about 10 C. Expensive, though, with Indium being about the price of silver, and Gallium being more than that. The alloys are considered non-toxic; they’ve replaced mercury in medical thermometers, for instance. Also, they tend to wet (stick to) everything, exactly UNLIKE mercury.
http://www.indium.com/products/fusiblealloys.php
Posted at 9:21 pm on Feb 16th, 2009 by WestfW