DESIGN OF AFM CANTILEVERS FOR COMBINED THERMOMECHANICALDATA WRITING AND READING

摘要

A Joule-heated atomic force microscope (AFM) cantileverrnwrites a data bit by scanning over a polymer substrate. Heat andrnforce applied to the polymer cause it to soften and flow, yieldingrnan indentation of radius near 50 nm. Data is read by measuring thernchange in temperature of the heated cantilever as it follows therncontour of an existing bit. Heat conduction governs the ultimaternperformance of a thermomechanical data storage device. Thernpresent work develops a finite-difference simulation of singlecantileverrnthermal and electrical behavior. Simulation resultsrnindicate design tradeoffs in power requirements, data writingrnspeed, and data reading sensitivity. Scaling of single-cantileverrnpredictions allows prediction of power requirements and ultimaterndata rates of cantilever arrays. The design tool predicts operatingrnpoints for the present array cantilever, as well as for a proposedrnarray cantilever. The framework established here considers for thernfirst time comprehensive thermal, mechanical, and system-levelrnrequirements for data writing and reading in a thermomechanicalrndata storage system.