A precision angular sensing system based on scanning tunneling microscopy (STM) is presented. The proposed system consists of three STM tips for the tracking of atoms of a reference lattice. This method will offer a real-time precision angular measurement system of pitch, roll and yaw with nano-radian resolution. The conceptual design is first described along with the computation of angles. A kinematic error analysis is also conducted for predicting the performance of the sensing system. A prototype system is described and experimental results involving atom tracking and angle measurements are presented. The proposed system achieves resolutions on the order of 1 nano-radian for all angle measurements. The strokes associated with the pitch and roll are on the order of 5/spl times/10/sup -5/ deg.
['Shigeru Sakuta', 'Kamal Youcef-Toumi']
A precision angular sensing system