Good vibrations? Nanomotion 'life detector' to hunt for extraterrestrial movement

A super-sensitive 'life detector' that uses a nano-sized cantilever to spot motion has arrived. Worth less than $10,000, it could prove especially effective in space exploration probes like the Mars rover, helping discover alien life on other planets.

Researchers at the Swiss Federal Institute of Technology in Lausanne (EPFL) say they are "calling ESA [European Space Agency] and NASA to see if they're interested."

A prototype would use very little battery power and could be contained in a box the size of a book.

If the so called 'life detector' had been available to the ESA's Philae lander, which detected organic molecules on the surface of its comet in November, it could have made a real breakthrough "determining if these conditions are still harboring life, in any form," Giovanni Longo, the lead author of the paper published in the Proceedings of the National Academy of Sciences (PNAS) told AFP in an email.

The key part of the motion detector - the microscopic cantilever - is basically a beam that is anchored only at one end, with the other end bearing a load. While the cantilever design is mostly used with bridges and buildings, this time around it is implemented on the micrometer scale. About 500 bacteria can be deposited on it.

"The nanomotion detector allows [for the] studying [of] life from a new perspective: life is movement," Longo said.

"This means that the nanomotion detector can detect any small movement of living systems and deliver a complementary point of view in the search for life," he added.

According to the scientists behind the technology - Giovanni Dietler, Sandor Kasas and Giovanni Longo - the system has already proven trustworthy with detecting bacteria, yeast and even cancer cells, and is currently being considered for the testing of drugs.

EPFL scientists say their simple, but "extremely sensitive" device can be built by adapting already-existing technology. The idea was inspired by the technology behind the atomic force microscope, a powerful machine which uses a cantilever to produce pictures of the very atoms on a surface. The cantilever scans the surface like the needle of a record player, while its movement is read by a laser to produce an image.

The motion sensor that the EPFL scientists have engineered works in a similar way, one difference is that the sample has to be attached on the cantilever itself.

For example, the scientists say, a bacterium attaches to the cantilever. If it's alive, it will inevitably produce some sort of movement. That motion will also move the cantilever and will be captured by the readout laser as a series of vibrations. The signal will be taken as a sign of life.

The EPFL scientists say they have successfully tested their innovation with isolated bacteria, yeast, and mouse and human cells. The cantilevers could be covered with bacteria or cancer cells and incubated with various drug compounds.

If the drugs are effective against the attached cells, the motion signals will reduce or cease altogether as the cells die off. According to the scientists, their new approach would be much quicker than current systems used in by pharmaceutical companies when looking for candidate antibiotics or anticancer drugs.

"The system has the benefit of being completely chemistry-free," Dietler says. "That means that it can be used anywhere - in drug testing or even in the search for extraterrestrial life."

"This is really the next step," Dietler believes.