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Researchers Create Ultrastretchable Wires Using Liquid Metal
hypnosec writes "By using liquid metal researchers have created wires that can stretch up to eight times their original length while retaining their conduction properties. Scientists over at North Carolina State University made the stretchable wires by filling in a tube made out of an extremely elastic polymer with gallium and an indium liquid metal alloy."
...to a manufacturer near you. Spaghetti wiring to complement their existing spaghetti code.
metallic gallium is not considered toxic
Wikipedia on Gallium
Pure indium in metal form is considered nontoxic by most sources.
Wikipedia on Indium
This sounds exactly like an indium-gallium strain gauge, which in turn is an evolution of the mercury-in-rubber strain gauge used for at least 30 years in medical measurements. These are rubber tubes filled with liquid metal, just like the "wires" described in this article. Their resistance increases as they are stretched, and they've been used for everything from monitoring respiration (wrapped around the chest) to monitoring blood pressure. A quick search on "Strain Gauge Plethysmography" will produce some relavent pages.
Thus this seems like a just a new use for an old technology. Am I missing something?
When they ditched mercury thermometers due to toxicity / envrionmental hazards, the replacement is galinstan - gallium, indium, and tin. So it is considerably less toxic.
Unfortunately it wets to glass, unlike mercury which beads up, and is more expensive.
The way around that is to coat the glass with something - I don't recall what now, but I think it was some gallium compound.
On the more expensive front - I'd think both gallium and indium are a couple orders of magnitude more expensive than copper, so don't count on that going away any time soon. (Not to mention copper itself is 'expensive' [~$5/kg, it varies], and manufacturers are cheaping out on it. 12 AWG booster cables?! What kind of sick joke is that?)
Sent from my PDP-11