Feature referenced tip localization in robotic nano manipulation

One of the prerequisite conditions for making a successful manipulation is that the relative position between the AFM tip and the objects can be sensed and controlled accurately. While this prerequisite is grandly hampered by the PZT nonlinearity and thermal drift. Although the PZT nonlinearity can be compensated to a certain extent through mounting a position sensor on the PZT scanner, this method leads to a higher system noise and a higher cost. In addition, this method can not handle the positioning error caused by thermal drift due to the lack of sensing ability to the displacement between the AFM tip and the sample stage. This paper propose a newly developed strategy to solve these problems. Its pivotal idea is the tip position is localized based on the sensing information to sample features, not PZT driving voltage or sensor signal. In this way, the positioning error aroused from PZT nonlinearity and thermal drift can be effectively suppressed. Experimental results demonstrate the advantage and effectiveness of the proposed method.