Researchers Create Ultrastretchable Wires Using Liquid Metal 94
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."
Re:The cross section changes (Score:4, Interesting)
so shouldn't this alter the conductivity of the 'wire'? http://en.wikipedia.org/wiki/Electrical_resistance_and_conductance#Relation_to_resistivity_and_conductivity [wikipedia.org]
One would think so.
But you could design for that, simply by using the smallest diameter as your critical dimension when selecting wire size.
Of course it also allows for some new circuit elements, those that can measure stretch via voltage drop, which might be very useful in robotics or prosthetics.
In short it might not be as much of a detriment as it is an advantage.
Isn't this 30 year old technology? (Score:4, Interesting)
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?