A MECHATRONICS APPROACH TO A DISPLACEMENT DEVICE OF NANOSCALE PRECISION

In ultra-precision machining and ultra-fine materials processing, the dimensional accuracy of manufactured parts is affected by the dynamical behavior of the positioning system, as the presence of vibrations can cause unwanted motion in any axis. Displacement sensors, like piezoelectric, capacitive or inductive sensors are mostly used in those applications, while for oscillation measurements of the vibrating beam in AFM-applications, Single Electron Transistors (SET's) are also applied. We propose a discrete displacement device by moving an anode toward a field electron emitter, which is sensitive down to a few nanometers of displacement stretch. Cold field electron emission from an array of nano-size cones grown on SiC is used, where the distance between the tip of emitting mounds and the counter-electrode (anode) is changed in the rhythm of the moving object under study.