ATOMIC-FORCE MICROSCOPE-BASED DATA-STORAGE - TRACK SERVO AND WEAR STUDY

The high spatial resolution of the atomic force microscope (AFM) has m otivated recent efforts to apply the technique to high-density data st orage. However, little attention has been given to satisfying the othe r necessary attributes required of any new data storage technology. Us ing a system based on reading topographic data features on a rotating disk with a high-frequency piezoresistive cantilever, we address sever al 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 unde r both load and tracking control with a disk velocity of 3 cm/s, 200 n m diameter marks are read continuously for over 145 h without any sign ificant change in signal amplitude. This represents a tip travel dista nce of 16 km, and each bit was read over 500 000 times.