A newly developed method might be able to detect sound waves produced by bacteria and other nano? and micro-objects NANOSYSTEMS INITIATIVE MUNICH
THE DEVICE: If a bacterium belches in a petri dish, does anyone hear it? In the January issue of Physical Review Letters, researchers at LMU Munich in Germany describe the world’s tiniest ear—an apparatus for the ultrasensitive detection of sound. By tracking the displacement of a levitating gold particle trapped in a focused laser beam, the team recorded the acoustic vibrations of nearby nanoparticles. The researchers were also able to determine from which direction the sound came.
The researchers estimate the nano-ear can detect sound levels as low as -60 decibels, making the device a million times more sensitive than human hearing.
WHAT'S NEW: Optical tweezers—infrared lasers focused through an optical microscope to trap tiny objects—are a standard tool used to study cells, metal particles, ...
