Modern computer systems require the storage of large amounts of digital data in an inexpensive, reliable and easily accessible way. Hard disk drives, consisting of one or more co-rotating hard disks with a magnetic head and a thin magnetic layer on the top surface of the disk, are the main non-volatile storage devices used in today’s computer systems. Disk drives were invented in the mid 1950teeth, when IBM designed the so-called RAMAC disk drive, consisting of 50 co-rotating disks of 600 mm (24 inch) diameter each, storing 5 Megabytes of data at a cost of approximately $100,000 per Megabyte. Typical modern hard disk drives store Terabytes of information, i.e., more than one million fold that of the 1956 RAMAC, on one to five 96 mm disks at a price of less than $100 per Terabyte. To achieve this dramatic growth in storage density, many engineering disciplines have contributed. Optimization of magnetic and tribological material problems is needed, along with an understanding of mechanics, fluid mechanics, tribology and control theory to design a transducer that flies approximately one or two nano-meters above the disk and is a mass-produced item with a mean time between failures on the order of millions of hours. High speed instrumentation, signal processing and an understanding of magnetic recording physics are further interdisciplinary aspects of hard disk drive technology.
Clearly, information storage on hard disks is a truly interdisciplinary field of research, belonging to the area of nano technology. A number of professors in the MAE department are involved with mechanics, materials and control aspects of disk drive technology and the design of the head disk interface, as well as the tribology and optimization of material properties. Many of these efforts are in cooperation with CMRR, the Center for Magnetic Recording Research. It is the goal of our information storage research to enhance the performance of future high storage density disk drives by a factor of ten to 100, keeping the rate of storage density increase as predicted by Moore’s law.