Advances in Macromolecular Data Storage

Abstract . We propose to develop a new method of information storage to replace magnetic hard disk drives and other instruments of secondary/backup data storage. The proposed method stores petabytes of user-data in a sugar cube (1 cm 3 ), and can read/write that information at hundreds of megabits/sec. Digital information is recorded and stored in the form of a long macromolecule consisting of at least two bases, 𝐴 and 𝐵. (This would be similar to DNA strands constructed from four nucleic acids ,the 𝐶,𝐴,𝑇𝐺.) The macromolecules initially enter the system as blank slates. A macromolecule with, say, 10,000 identical bases in the form of ....𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴 may be used to record a kilobyte block of user-data (including modulation and error-correction coding), although, in this blank state, it can only represent the null sequence 00000....000. Suppose this blank string of ’s is dragged before an atomically𝐴 -sharp needle of a scanning tunneling microscope (STM). When electric pulses are applied to the needle in accordance with the sequence of 0s and 1s of a 1 𝑘𝐵 block of user-data, selected 𝐴 molecules will be transformed into 𝐵 molecules (e.g., a fraction of will be broken off and discarded). The resulting string now encodes the 𝐴user-data in the form of 𝐴𝐴𝐵𝐴𝐵𝐵𝐴...𝐵𝐴𝐵. The same STM needle can subsequently read the recorded information, as 𝐴 and 𝐵 would produce different electric signals when the strand passes under the needle. The macromolecule now represents a data block to be stored in a parking lot“ ” within the sugar cube, and later brought to a read station on demand. Millions of parking spots and thousands of Read/Write stations may be integrated within the micro-fabricated sugar cube, thus providing access to petabytes of user-data in a scheme that benefits from the massive parallelism of thousands of Read/Write stations within the same three-dimensionally micro- structured device.