TIP-BASED DATA-STORAGE USING MICROMECHANICAL CANTILEVERS

We describe a micromechanical approach to data storage based on the at omic force microscope. The approach uses a sharp tip on the end of a s oft micromachined cantilever. The tip sits in contact with a polymer s ubstrate which contains topographic features representing data. Writin g is performed by heating the tip with a laser, which softens the poly mer substrate and allows the tip to create a pit. Reading is done by m easuring the small deflection of the cantilever as the tip rides over the feature. In this way, areal densities more than 20 times that of o ptical recording have been achieved. For this purpose, we have fabrica ted Si3N4 cantilevers with integrated pyramidal tips which have mass a s low as 0.3 ng, 30 times less mass than the smallest commercially ava ilable cantilevers. With these cantilevers, we have demonstrated readi ng real data at rates exceeding 1 Mbit/s.