In Physical Review Letters, three physicists, headed by Leiden professor Michel Orrit, describe a microphone that consists of just one molecule: a molecule of the substance Dibenzoterrylene (DBT) adhered to a "tuning fork" of quartz. DBT is fluorescent, which means that if you shine a light on it, it will radiate light in another colour, just like blacklight paint. The light emitted by the DBT molecule changes a tiny little bit if the crystal it is on starts to vibrate. We can measure that changing light. Although the microphone itself is only the size of a molecule, it requires quite a lot of kit: a laser, a spectrometer, a tuning fork and the equipment to chill everything to one and a half degrees above absolute zero. But then, you truly have something that can measure tiny vibrations and is therefore handy for all sorts of physics experiments on the nanoscopic scale, according to the researchers.
Background
Nanomicrophone
Wednesday 15 October 2014