Trapped micro-cylinders act a bit like neurons
Researchers from TU Delft's Kavli Institute of Nanoscience and the Institut Non Linéaire de Nice, have shown that certain physical properties of rotating microscopic cylinders resemble those of communicating neurons, for example.
Both the micro-cylinders and the neurons are 'excitable', i.e. they respond to an external disturbance by producing a pulse (e.g. a voltage) of a given, fixed size. The results of this study was published online on the Nature Physics website on December 19th.
Simultaneously, the researchers have shown that the rotating micro-cylinders can detect the presence of microscopic particles in liquid. This is because the presence of such particles in the vicinity of a rotating micro-cylinder produces a clearly measurable disturbance in the torque experienced by the cylinder. This provides a means of detecting, counting, or separating cells (or other microscopic particles) in liquids.
For the purposes of this study, the researchers employed optical torque tweezers. This unique instrument is capable of measuring both the force and angular momentum exerted on microscopic objects, including biological molecules such as DNA.