I for one, welcome our liquid metal overlords....
Say no more.
Top boffins in Germany and China say they have developed a remarkable new type of material which can switch from being strong and hard to soft and squashy at the touch of a button. Jörg Weißmüller, materials scientist at both the Technical University of Hamburg and the Helmholtz Geesthacht Zentrum für Material- und …
By "Friction free" - i think he is alluding to "lossless" - hence my original sarcastic comment.
Almost every automatic car has a "torque converter" which converts engine torque into heat, which i would class as liquid friction, it gets hot right? Magnetic drag plates operate similarly, with eddy current heating in the slip plate taking up the slack between engine energy and propulsion output. Fundamentally, when the car is at rest and the engine power is applied, there is energy input but no energy output (for the first fraction of a second) - hence loss hence friction. As the car speeds up the losses drop to zero.
So, fundamentally, due to the fact that a clutch needs to be used on a hill-start, to hold the car stationary for a moment, there will always need to be some power dissipated, hence the concept of a frictionless (i.e. lossless) clutch is a null concept.
that instead of having a plate that rubs against the fly wheel, replace the whole unit with a liquid that when a switch is flicked it becomes solid thus binding engine to gear box... as there are no rubbing together of parts this is friction free....
I did indeed see such a device demonstrated on TV many years ago but it was a plastic and in its solid form was more of a thick soup and did not become solid enough to have any practical applications.
so a friction free clutch is one that would not wear out due to the erosion of the friction pads !!
the problem with some people is they think to much !
Been done. You have a tank of metal powder and blow a jet of it out over a laser. You move the nozzle / laser head around to make the part.
Seen an engine block with a crack in it repaired using the technology to show it off (I think it was at Photonics expo by one of the Manchester Unis about 14 years ago)
Gold dissolves in a mixture of nitric and hydrochloric acid to form chloroauric acid. If you heat chloroauric acid, it gives off hydrogen chloride and leaves behind auric chloride. React auric chloride with trisodium citrate to get back to metallic gold.
If you want do destroy gold properly, send it to LHC or RHIC.
... the method used by Niels Bohr to stop his colleagues' Nobel Prize medals being looted by the Nazis?
Apparently, the solution stayed in a flask, undetected, in a lab for the duration of the war, and afterwards the process was reversed, and the recovered gold sent to Stockholm to be struck into replacement medals.
Incidentally, it seems to me from El Reg articles over the past few years that Ze Germans are the only nation in Europe that is churning out some serious kick-ass science with real-world applications. No wonder their economy is doing so well compared to <ahem> countries cutting their Science and R&D budgets </ahem>
I've been trying think of applications.
If the change from rigid to soft also reduces the tensile strength sufficiently that a bar of the material will break, under a stress which it can support in the rigid state, then it's a potential replacement for explosive bolts, for example.
It would also have been an, albeit expensive, candidate for the release mechanism developed for the PARIS project:
The rather elegant low-tech system finally (and successfully) used:
Another thing that occurs to me is collision-mitigation systems, such as crumple zones and (non-Bulgarian) airbags. Now if your engine could instantly change from being a massive lump of solid metal into something as soft as a cuddly toy...
can this be made to work with less conductive materials too? If so, we could conceivably have Neal Stephenson's "armorgel" from Snow Crash.
better armor for joints that doesn't impede comfort or flexibility, especially if it can work as well for big joints like neck or back, as well as smaller ones like fingers and wrists, are always welcome by the long distance and daily-commute motorcycle community.
Didn't I read a while back about "magnetic solder" being the next wonder material?
Seems to be easy to make, just mix finely powdered Sn, Ag and Cu (aka SnAgCu with 300 mesh iron particles and then fuse together under inert gas to form the solder.
This then melts nicely using an induction field and can be moved around using a magnet.
Its not much of a stretch to slightly modify this formula by replacing the silver with gallium and indium i.e galinstan, then you too can have your very own "Mimetic Polyalloy" hand rising out of a pool of metal to scare the bejesus out of honest Machine Uprising-fearing folks :-)
(btw, gallium tends to wet glass annoyingly, the fix is to use gallium oxide on the surface.)
AC, because someone will probably figure out how to turn this into a pocket stabbing weapon/lock pick/etc...