GPS+ on the Nanometer Scale
A new technique makes it possible to track not only the location of moving particles to within 10 nanometers, but also their rotation and orientation. This is like watching a football game from the ionosphere and knowing where the football is at anytime within 1.5 inches, how the ball is spinning, and what direction it is moving. This is made possible by inserting an additional arm into the optical path of the specialized instrument known as a differential interference contrast microscope used for visualizing motion. This addition makes it possible to operate in two modes simultaneously; one mode focuses on particle location while the other focuses on rotation and orientation. Images can be taken every 75 milliseconds, 4 times faster than a blink of an eye. The new technique will aid researchers looking to understanding particle movement in nanoengineered environments and within cells involved in important processes such as carbon fixation.