hesela.devThermomechanical probe storage
Thermomechanical probe storage records data as nanoscale indentations in a polymer film, using heated scanning probes to write and sense them.
Mechanism: A heated tip and applied force form an indentation. Readout uses heat loss across the gap to the medium: entering a pit changes the heater temperature and electrical resistance. Each probe addresses its own field through mechanical scanning. [1] [3]
Historical results: The 2000 demonstration separated single-probe densities of 400-500 Gb/in2 from 100-200 Gb/in2 with a 32 x 32 array. The 2002 paper reported single-probe density up to 1 Tb/in2. These are different experimental scopes, not the capacity of a shipped drive. [1] [2]
In 2008, a prototype recovered three 1024-byte sectors stored across four data fields at a reported effective density of 840 Gb/in2. The detected symbol error rate was approximately 10^-4 before ECC; the demonstrated sector output was error-free after ECC. Successful decoding does not mean the physical channel made no errors. [4]
Parallelism: Fabricated probe count, simultaneously addressed probes and user throughput are distinct. The 2003 design example used 256 active probes, a 5-microsecond symbol interval and constrained coding to obtain 34.1 Mbit/s; this was a design calculation. [3]
Relations
- related
- Areal density
Limitations
- Tip and medium wear, long-term indentation stability and the power cost of parallel operation require separate engineering evaluation. [3]
- Writing a nearby indentation can partly erase an existing one, so smaller spacing changes the recording channel as well as density. [4]
Citations
- Vettiger et al.: The Millipede - More than one thousand tips for future AFM data storage, IBM J. Res. Dev. 44 (2000), pp. 323-340
- Vettiger et al.: The millipede - nanotechnology entering data storage, IEEE Transactions on Nanotechnology 1 (2002), pp. 39-55
- Eleftheriou et al.: A Nanotechnology-based Approach to Data Storage, VLDB 2003, sections 2-4 and Figure 6
- Pantazi et al.: Probe-based ultrahigh-density storage technology, IBM J. Res. Dev. 52 (2008), pp. 493-511
Sources & caveats
- Historical research architecture, not a current product-availability claim. No universal invention date or commercial launch is assigned.
- c1 sections 2-3 and 8 distinguish probe operation from array results; c3 sections 2-4 distinguish fabricated components, measured signals and design projections.
- c2 was checked through the IBM Research abstract and institutional bibliography; its full paper was not used for detailed mechanisms.
- c4 was read in the author-uploaded full text, especially pp. 499 and 505-507. The detailed sector demonstration is narrower than the prototype's supported parallelism.
- The 2008 reported pre-ECC rate is approximate; no count-based confidence interval, fleet failure rate or lifetime extrapolation is inferred.