Would you buy a lightweight wristwatch MP3 player that holds 150-300 albums worth of music? IBM scientists say they have created a data-storage technology that can store the equivalent of 200 CD-ROM's on a surface the size of a postage stamp. Writing in the current issue of the journal IEEE Transactions on Nanotechnology, researchers at IBM's laboratories in Zurich report that they have achieved a storage density of one trillion bits of data per square inch, about 25 times as great as current hard disks. Dr. James C. Ellenbogen, an expert on molecular electronics at the Mitre Corporation in McLean, Va., described the work as "incredible engineering." ... IBM project leader: The storage technology could cram 10 to 15 gigabytes of data into a tiny format that would fit in a multifunctional wristwatch. Here is the abstract from the IEEE paper: We present a new scanning-probe-based data-storage concept called the "millipede" that combines ultrahigh density, terabit capacity, small form factor, and high data rate. Ultrahigh storage density has been demonstrated by a new thermomechanical local-probe technique to store, read back, and erase data in very thin polymer films.With this new technique, nanometer-sized bit indentations and pitch sizes have been made by a single cantilever/tip into thin polymer layers, resulting in a data storage densities of up to 1 Tb/in2. High data rates are achieved by parallel operation of large two-dimensional (2-D) atomic force microscope (AFM) arrays that have been batch-fabricated by silicon surface-micromachining techniques. The very large-scale integration (VLSI) of micro/nanomechanical devices (cantilevers/tips) on a single chip leads to the largest and densest 2-D array of 32x32 (1024) AFM cantilevers with integrated write/read/erase storage functionality ever built. Time-multiplexed electronics control the functional storage cycles for parallel operation of the millipede array chip. Initial areal densities of 100-200 Gb/in2 have been achieved with the 32 32 array chip, which has potential for further improvements. A complete prototype system demonstrating the basic millipede functions has been built, and an integrated five-axis scanner device used in this prototype is described in detail. For millipede storage applications the polymer medium plays a crucial role. Based on a systematic study of different polymers with varying glass-transition temperatures, the underlying physical mechanism of bit writing has been identified, allowing the correlation of polymer properties with millipede-relevant parameters. In addition, a novel erase mechanism has been established that exploits the metastable nature of written bits. |