Millipede memory
IBM demonstrated a prototype millipede storage device at CeBIT 2005, and was trying to make the technology commercially available by the end of 2007.
DRAM basically consists of a series of capacitors, which store data in terms of the presence or absence of electrical charge.
As a result, a hard drive's performance is limited by the mechanical speed of the motor, and it is generally hundreds of thousands of times slower than DRAM.
Also similar to hard drives, millipede's physical medium stores a bit in a small area, leading to high storage densities.
Mechanically, millipede uses numerous atomic force probes, each of which is responsible for reading and writing a large number of bits associated with it.
These bits are stored as a pit, or the absence of one, in the surface of a thermo-active polymer, which is deposited as a thin film on a carrier known as the sled.
These actuators are similar to those that position the read/write head in a typical hard drive, however, the actual distance moved is tiny in comparison.
Thus, many such field/probe pairs are used to make up a memory device, and data reads and writes can be spread across many fields in parallel, increasing the throughput and improving the access times.
In the case where there is no pit at that location, only the very tip of the probe remains in contact with the sled, and the heat leaks away more slowly.
Older experimental systems used a variety of erasure techniques that were generally more time consuming and less successful.
However, the exact amount is dependent on the speed that data is being accessed; at slower rates the cooling during read is smaller, as is the number of times the probe has to be heated to a higher temperature to write.
When operated at data rates of a few megabits per second, Millipede is expected to consume about 100 milliwatts, which is in the range of flash memory technology and considerably below hard drives.
Experiments done at IBM's Almaden Research Center showed that individual tips could support data rates as high as 1 - 2 megabits per second, potentially offering aggregate speeds in the GB/s range.
