Looking for life on other planets usually relies on chemical detection, which might be limited or even irrelevant to alien biology. On the other hand, motion is a trait of all life, and can be used to identify microorganisms without any need of chemical foreknowledge. Scientists from the Swiss Federal Institute of Technology in Lausanne (EPFL) have developed an extremely sensitive yet simple motion detector that can be built easily by adapting pre-existing technology. It has proven accurate with detecting bacteria, yeast, and even cancer cells, and could be used for the rapid testing of drugs and even the detection of extraterrestrial life. The system uses a nano-sized cantilever to detect motion. A sample, such as a bacterium, is attached to the cantilever itself. If the bacterium is alive, it will inevitably move in some way - it may move its flagellum or simply carry out normal biological functions. That motion also moves the much smaller and sensitive cantilever and it is captured by the readout laser as series of vibrations. The signal is taken as a sign of life.