Information Storage and Retrieval using Macromolecules as Storage Media

Introduction. To store information at extremely high-density and data-rate, we propose to adapt, integrate, and extend the techniques developed by chemists and molecular biologists for the purpose of manipulating biological and other macromolecules. In principle, volumetric densities in excess of 10 bits/cm can be achieved when individual molecules having dimensions below a nanometer or so are used to encode the 0’s and 1’s of a binary string of data. In practice, however, given the limitations of electron-beam lithography, thin film deposition and patterning technologies, molecular manipulation in submicron dimensions, etc., we believe that volumetric storage densities on the order of 10 bits/cm (i.e., petabytes per cubic centimeter) should be readily attainable, leaving plenty of room for future growth. The unique feature of the proposed new approach is its focus on the feasibility of storing bits of information in individual molecules, each only a few angstroms in size. Nature provides proof of principle for this type of data storage through the ubiquitous existence of DNA and RNA molecules, which encode the blueprint of life in four nucleic acids: Adenine, Guanine, Cytosine, and Thymine/Uracil. These macromolecules are created on an individual basis by enzymes and protein-based machinery of biological cells, are stable over a fairly wide range of temperatures, are read and decoded by ribosomes (for the purpose of manufacturing proteins), and can be readily copied and stored under normal conditions. Advances in molecular biology over the past decades have made it possible to create (i.e., write) artificial molecules of arbitrary base-sequence, and also to decode (i.e., read) such sequences. These techniques can now be adapted and extended in the service of a new generation of ultra-high-density data storage devices. Macromolecular strings (representing blocks of data several megabytes long) can be created on-demand, then stored in secure locations (parking spots) on a chip. These data blocks can then be retrieved by physically moving them to decoding stations (also located on the same chip), subjecting them to a “read” process, then returning them to their secure parking spots until the next request for readout is issued, or until there is a call for their removal and destruction (i.e., erasure).