PDL Abstract

MEMS-Based Integrated-Circuit Mass-Storage Systems

COMMUNICATIONS OF THE ACM, Vol.43, No.11., November 2000.

L. Richard Carley, Gregory R. Ganger and David F. Nagle

Dept. Electrical and Computer Engineering
Carnegie Mellon University
Pittsburgh, PA 15213


Abandoning the rotating disk paradigm, simple miniature microelectromechanical systems position probe tips over the storage media, potentially creating a new generation of nonvolatile rewritable mass storage devices, as well as support for multitude of "intelligent" gadgets. Disk drives' 100+%-per-year capacity growth rate continues to outpace the 60%-per-year growth rate of semi-conductor memories, according to the semiconductor industries association, allowing disk drives to maintain and reinforce their status as the most cost-effective nonvolatile storage solution available for computers and for future consumer electronics products. Unfortunately, decreases in disk drive access times have been minimal, creating a significant performance problem for common applications accessing many small pieces of data, such as those in transaction-processing workloads. However, though the minimum entry cost of disk drives has declined in recent years due to decreases in the number of disks and heads per drive, their cost is still much too high for many consumer applications.

In order for mass-storage devices to pierce both the access-time and entry-cost barriers, researchers have turned to hybrid approaches leveraging the best of both semiconductor memories and disk drives. From semiconductor memories, the hybrid approaches have adopted the parallel wafer-fabrication process that keeps unit costs low. From disk drives, the hybrid approaches have adopted recording heads using mechanical positioning to address data stored on thin-film material instead of the lithographic definition required by today's semi-conductor memories. But for compatibility with silicon-wafer-fabrication processes, these hybrid approaches typically abandon the rotating disk paradigm in favor of simple microelectromechanical systems (MEMS) to position probe tips over the storage media.