DNA-based memory device and method of reading and writing same

A method of reading and writing molecular-based memory devices comprising:

• providing a substrate comprising a first surface, said first surface comprising a first functionality located on the first surface at a computer memory cell address;
• providing an atomic force microscope (AFM) arm comprising an AFM tip;
• attaching at least one first polynucleotide to the AFM tip,
• causing the first polynucleotide to approach a second polynucleotide, the second polynucleotide comprising the complementary base sequence of the first polynucleotide and further comprising a second functionality, the second functionality being capable of reacting with the first functionality so as to form a bond;
• assigning a value to the second polynucleotide according to the base sequence of the second polynucleotide, wherein the value assigned to the second polynucleotide represents a memory bit in a computer memory;
• forming a double strand DNA helix comprising the first polynucleotide and the second polynucleotide, wherein the attractive forces between the first polynucleotide and the second polynucleotide are less than the attractive forces providing the attachment between the first polynucleotide and the AFM tip;
• forming a bond between the first and second functionalities, wherein the attractive forces between the first polynucleotide and the second polynucleotide are less than the attractive forces providing the bond between the first and second functionalities;
• and
• increasing a distance between the AFM tip and the first functionality such that the double strand DNA helix is pulled apart, the first polynucleotide remaining attached to the AFM tip, and the second polynucleotide remaining attached to a substrate surface, thereby assigning the value of the second polynucleotide to a computer memory cell at the computer memory cell address.