Device Detects Subatomic-Scale Motion

It is relatively easy to measure small movements of large objects, but is much more difficult when the moving parts are on the scale of nanometers, or billionths of a meter. The ability to accurately measure tiny displacements of microscopic bodies has applications in sensing trace amounts of hazardous biological or chemical agents, perfecting the movement of miniature robots, accurately deploying airbags, and detecting extremely weak sound waves traveling through thin films.