People often state that certain planets are too hot, cold or toxic to support life. The catch, however, is that those people are really just talking about life as we know it here on Earth. By that same token, when rovers exploring other planets seek out chemical signatures associated with life forms, they're only able to identify chemicals that we know to look for. That's why Swiss scientists from the EPFL research center have created a device that identifies microscopic life, based on nanoscale movements instead of chemistry.
Developed by researchers Giovanni Dietler, Sandor Kasas and Giovanni Longo, the ultra-sensitive motion sensor utilizes technology that's already used in the atomic force microscope.
In the case of the microscope, a tiny sharp-tipped probe is moved across the surface being imaged. That probe takes the form of a cantilever – one end is secured to the microscope, while the other (the pointy end) is free to move up and down as it's affected by the contours and other properties of the surface. The microscope uses a laser to measure those minuscule movements, and proceeds to create an image of the surface based upon them.
On the EPFL motion sensor, a tiny cantilever extends out horizontally from the device. When microscopic living items such as individual cells or bacterium are placed on its free end, even their regular metabolic functions will cause the cantilever to vibrate. As with the microscope, those movements are detected via a laser.
When testing the system, the scientists were able to detect movement in items such as bacteria, yeast, mouse and human cells. They were also able to detect and isolate organisms from soil and water samples, which stopped producing readings once drugs were used to kill them.
In the immediate future, suggested applications for the technology include things like drug development. For that particular scenario, live bacteria or cancer cells could be placed on a cantilever and then subjected to a medication intended to eradicate them – the sensor would let researchers know how thoroughly the medication did its job.
Down the road, however, the EPFL team would indeed like to see arrays of the motion sensors installed on vehicles like the Curiosity Rover, helping to search for extraterrestrial life. That's assuming that life forms on other planets do move, even if just a little bit.
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.
Source: EPFL
