IBM research explores Lilliputian limits
by Luc Morris
Tim Reiley, head of Micromechanics at IBM's Almaden Research Center in
San Jose, and Chairman of the IBM Micromechanics Council,
shudders at mention of the word "nanotechnology."
"Nanotechnology (technology at the nanometer level) has
been hyped up a lot. We prefer the home-grown term
'micromechanics' because we do practical work more at the micron
level," he says.
Almaden, as well as IBM labs at Yorktown, Zurich, and Tokyo,
carry out industry-leading research in the area of MEMS, or
Microelectro Mechanical Systems.
Micromechanics in storage
As the areal density of data
storage on disks continues to grow at the breakneck pace of 50-60
percent a year, disks with storage of 10 gigabytes per square
inch will likely be commercially available in five to seven
years, according to Reiley.
At this storage density, the space between tracks on the disk
surface will approach one micron (.000001 meter). As data gets
closer together on the disk, the read-write head will need to be
able to move over the disk surface with more precision.
Almaden researchers, with Long-Sheng Fan at the helm, are
working on a microactuator to solve this
problem. Recording heads would use a two-stage actuator to move:
a conventional actuator would move the entire head and arm, and a
microactuator would move the head only (where the recording
sensor is) with fine precision to the exact location over the
disk surface.
Although research into micromechanics and storage is
relatively new, "this research (micromechanics) will become
very important when disks reach the 10-20 gigabyte per square
inch range," explains Reiley.
At the same time, Almaden research has developed the microfile
(see picture). About the size of a quarter, the microfile will
hold 1GB of data at current storage densities. Microfile technology is now being used in
cameras, printers, hand-held communicators and digital picture frames -- areas where
magnetic storage will be cheaper than alternative semiconductor
storage.
The Atomic Force Microscope probe
The second area of Almaden research in micromechanics is led
by Dan Rugar. Magnetic and optical storage density will continue
to increase until it hits a physical limit. At that point, a new
technology will be needed to further increase storage density.
Current research uses an AFM-based probe to
create and detect fine pits in a storage medium. As the AFM tip
is pressed against the disk surface, a probe-heating laser (to
write) and a motion detection laser (to read) work together to
allow very high density storage.
Almaden research by Dan Rugar, Jonathon Mamin, and Bruce
Terris has already demonstrated data storage density of 25
gigabytes per square inch, with a data reading rate of one
megabyte per second, using this method.
"Micromechanics is a technology that IBM only began to
focus on five years ago," says Reiley. "But, with disk
storage density increasing at current rates, this is going to be
very, very important in the near future."
Maybe then we can hype micromechanics a little.
The 4-Million Mirror Chip
Another IBM advancement has come in the form of a seemingly unrelated to computers discovery--the 4-million mirror chip.
