Atomic forcemicroscope-based data storage: Track servo and wear study

The high spatial resolution of the atomic force microscope (AFM) has motivated recent efforts to apply the technique to high-density data storage. However, little attention has been given to satisfying the other necessary attributes required of any new data storage technology. Using a system based on reading topographic data features on a rotating disk with a high-frequency piezoresistive cantilever, we address several of these issues. A timing-based control method for data tracking is demonstrated and shown to maintain the radial tip position to within a standard deviation of 31 nm. While maintaining the tip position under both load and tracking control with a disk velocity of 3 cm=s, 200 nm diameter marks are read continuously for over 145 h without any significant change in signal amplitude. This represents a tip travel distance of 16 km, and each bit was read over 500 000 times. © 1998 Springer-Verlag.