Noise Resistant Full Adder Using DNA Strands

Abstract

A DNA computer requires DNA processor. A fundamental component of the processor is an arithmetic logic unit (ALU). The ALU performs all arithmetic operations in binary format, and the most critical operation is two's complement addition, which can involve addition, subtraction, multiplication, and division. Two's complement adders can be synthesized using multiple full adders. In this paper, a noise-resistant DNA computing full adder circuit is presented. The proposed adder circuit, unlike other circuits, takes strands as inputs and produces the results in the form of DNA strands. This is an important characteristic, since it enables multiple-level design. In addition, since all possible hybridization in this circuit is desired, it can control an abundance of unwanted strands. As a result, the synthesized adder is noise-resistant. While other multi-level designs might be possible (e.g., Nor-Nor design), the proposed design implements the full adder circuit as an integrated gate. The benefit of having an integrated circuit is that it eliminates the need for separate suppressors and activators. Before synthesizing the adder, we implemented AND, OR, and inverter gates and then extended these basic components to implement the desired circuit. The proposed designs were implemented and tested using Visual DSD programming and simulation tool.