Millipede is a type of non volatile memory developed by IBM, which is stored on nanoscopic pits burned into the surface of a thin polymer layer, read and written by MEMS(Micro electrical mechanical system) probes.
Promises a data density of more than 1Tb/sq. inch.
Potential replacement for magnetic recording in hard drives.
The name ‘Millipede’ basically is derived from the way it works.
Thousands of sillicon tips sit on the thin polymer surface, leaving pits.
Data is stored in a ‘Dumb’ medium, i.e simpler and smaller than any cell.
Uses numerous nanoscopic head which can read and write in parallel.
Atomic Force Probes used, each responsible for reading and writing of large no. of bits associated with it
Bits are stored in pits as a thin layer called ‘Sled’ in the surface of a polymer.
To position the pits according to the sillicon probes, the sled is moved in a X/Y scanning pattern.
Multiplex drivers allow addressing of each tip individually.
Probe tip is heated to around 300 °C and moved
in proximity to the data sled.
If there is a pit, the probe is pushed inside it and it cools faster.
In absence of a pit, the cooling is slower.
Electrical resistance is a function of changing temperature.
Low resistence is translated to logic ‘1’, and higher to logic ‘0’.
Probe is heated to a temperature above the glass transition temperature of the polymer (around 400 °C).
To write ‘1’ the tip is gently touches the surface causing a dent.
To erase the bit and return it to zero state, the tip is pulled up from surface.
The write or overwrite cycles are limited to 1,00,000 cycles.
Cantilevers have integrated tip heating for thermo
It consists of the heater platform with the tip on top, legs acting as a soft mechanical spring and an electrical connection to the heater.
Bending as well as the tip height must be well controlled in order to maintain an equal loading force for all cantilevers of an array.
Storage capacity – 1 terabit per square inch.
Uses atomic force probes.
Data reads & writes in the storage field.
Data rate is 1Gb/s.
Needs less power about 100mw.
Millipede systems can be used for micro drives, which will feature very small form factor, enabling use in small footprint devices like watches, mobile phones and personal media systems, and at the same time provide high capacity.
High-capacity hard drives
The Millipede system provides high data density, low seek times, low power consumption and, probably, high reliability. These features make them candidates for building high capacity hard drives, with storage capacity in the range of terabytes.
Current state of the art:
The progress of millipede storage to a commercially useful product has been slower than expected. Huge advances in Flash and harddrives, has made the existing demonstrators unattractive for commercial
Millipede appears to be in a race, it has not been surpassed by newer generations of the existing technologies by the time it is ready for production.
Millipede is rewritable, and it may eventually enable storage of over 1.5 GB of data in a space no larger than a single hole in the punch card.
There is not a single step in fabrication that needs to be invented.