Mechanical storage goes low power

Researchers from the LG Electronics Institute of Technology in Korea have devised a very low-power method of reading bits of information stored in areas of film that measure 50 nanometers, or 20 times narrower than an E. coli bacterium.

The method could eventually be used in ultrahigh-density mechanical storage devices for portable systems like notebook computers, personal digital assistants and digital cameras.

The researchers' thermopiezoelectric cantilever consists of a heated silicon tip and piezoelectric sensor. Data is written to a thin polymethylmethacrylate film by forming an indentation with the heated tip. Data is read from the film by the piezoelectric sensor as the cantilevered scans across the indentations. Piezoelectric systems convert mechanical force to electricity and vice versa.

Key to the method is that the piezoelectric sensor does not require any power when sensing, making the device lower-power and faster than similar methods such as IBM's Millipede, which reads data by measuring thermal rather than piezoelectric conductance changes between the heater platform and the polymer media, according to the researchers.

The thermoelectric cantilever could be used practically in five or six years, according to the researchers. The work appeared in the December 8, 2003 issue of Applied Physics Letters.