Improve Capability of DNA Automaton: DNA Automaton with Three Internal States and Tape Head Move in Two Directions

DNA automaton is a simple molecular-scale automaton, in which the converting of information deploys in molecule-scale by DNA and DNA-manipulating enzymes autonomously. Finite automaton with two internal states has been applied to medical diagnosis. This paper analyses the computation ability of DNA automaton with different enzymes and the possibility of DNA finite automaton with three internal states which is more powerful than the two internal states finite automaton. Finally, we describe a DNA finite automaton with three internal states and proposal a scheme of DNA automaton model in which the tape head can move forward and backward, and symbols can be read from and write into the tape, thus extend the computation ability of DNA automaton and its application fields.