It is thought that one day tiny satellites known as nanosatellites could propel themselves in space by expelling fine streams of liquid, in the same way that a squid shoots jets of water to move itself forward.
At the moment researchers use tiny, fragile needles to build tiny jet propulsion systems but these are expensive. However, researchers at the Michigan Technological University have found a better solution in something called ferrofluid; a magnetic liquid that can form itself into needles that can act in the same way.
These ferrofluids are flat until exposed to a magnet, at which point they form spikes. These remain in place no matter whether the fluid is shaken or turned. They are also self-healing, meaning the spike will reform if it gets broken.This is a useful characteristic seeing as a nanosatellite needs a few hundred spikes despite measuring only a few inches across.
Nanosatellites need to be robust in order to survive the trip in to space and also the return journey to Earth.
“Because they are so small and intricate, they are expensive to make, and the needles are fragile,” Michigan Technological University mechanical engineering professor Brad King said in a release. “They are easily destroyed either by a careless bump or an electrical arc when they’re running.”
Mr King has applied for a patent and continues to research ferrofluids for nanosatellites.
“First we have to really understand what is happening on a microscopic level, and then develop a larger prototype based on what we learn,” King said in the release. “We’re not quite there yet; we can’t build a person out of liquid, like the notorious villain from the Terminator movies. But we’re pretty sure we can build a rocket engine.”
[Image via wikimedia]