4 ms·
When placed in a solution of sodium hydroxide, or even brine, and kept in contact with a flake of aluminium for "fuel", it moves around for about an hour. So n
by antsar 12y ago
When placed in a solution of sodium hydroxide, or even brine, and kept in contact with a flake of aluminium for "fuel", it moves around for about an hour.
So not quite self-powered.
- dang 12y agoWe took "self-powered" out of the title.
- samatman 12y agoChemist here: I think that's overly editorial. If there were an air-burning engine made of aluminum, which consumed itself for motive force, we might describe that as self-fueled. In general the reducing agent is considered fuel and the oxidizer is assumed; a motor that oxidizes aluminum using hydroxide is not that different from one that oxidizes it using oxygen. Edit: The flake of aluminum fuel physically gloms onto the motor, and aluminum will normally form an oxide that would prevent hydroxide (certainly brine) from reducing it. It's not a 'mere' fuel that's physically driving the droplet, there's a single reaction happening. My hunch is that's where the tin comes in.
- dang 12y agoThanks for the great comment! We put 'self-fueled' back in the title.
- zafka 12y agoPretty sure the tin is just to help get the low temperature eutectic of Galinstan. I am pretty sure mercury would work just as well, but children and grad students don't get to play with Mercury much any more.
- deleted 12y ago[deleted]