RESEARCH ARTICLE
Copyright © 2011 American Scientific Publishers
All rights reserved
Printed in the United States of America
Journal of
Computational and Theoretical Nanoscience
Vol. 8, 1–8, 2011
Half Adder and Half Subtractor Operations by
DNA Self-Assembly
Yanfeng Wang
1 2 ∗
, Junwei Sun
2
, Xuncai Zhang
1 2
, and Guangzhao Cui
1 2
1
Research and Development Center of Biological Information Technology, Zhengzhou University of Light Industry,
Zhengzhou, 450002, China
2
College of Electrical and Electronic Engineering, Zhengzhou University of Light Industry,
Zhengzhou, 450002, China
Recently, experiments have demonstrated that the simple binary arithmetic and logical operations
can be executed by the process of self-assembly of DNA tiles. This paper brings out the realization
of the half adder and half subtractor using DNA self-assembly with parallel logical operations, in
much the way that a general-purpose computer can employ the simple logical circuits for a variety of
applications. The DNA self-assembly that we describe here are fundamentally the simple example,
but it seems possible to extend more complex logical circuits.
Keywords: DNA Self-Assembly, DNA Computation, Half Adder, Half Subtractor.
1. INTRODUCTION
In the past few decades, the traditional silicon-based com-
puter has made great contributions to the progress and
development of human society. But due to optical wave-
length limitations in conventional lithographic fabrication
techniques and physical limits, silicon-based technology
improvements will soon begin to approach their ultimate
limits in the rapidly approaching future. In the traditional
silicon-based computers, information processing in digi-
tal systems is straightforward and based on very simple
principles of Boolean logic. Logic gates are the devices
which are used to perform basic logical operations and
are the basis of the traditional silicon-based computer
processors, which perform logic and arithmetic opera-
tions between Boolean variables. Having a size more than
100 times smaller than the conventional silicon gates,
molecules offer excellent component minimization poten-
tial. The rapid emergence of DNA nanotechnology in
recent years has aroused much excitement among scien-
tists due to DNA self-assembly, as the most advanced and
versatile system, which has been experimentally demon-
strated for programmable construction of patterned sys-
tems on the molecular scale, and provides means to extend
Moore’s Law beyond the foreseen limits of small-scale
conventional silicon-based integrated circuits.
The notion of computation by interacting tiles dates
from Wang
1
in the 1960s. The use of stable branched DNA
∗
Author to whom correspondence should be addressed.
molecules containing sticky ends (DNA tiles) to produce
multidimensional constructs was proposed in the early
1980s.
2
Winfree
3
suggested using Wang tiles based on
branched DNA molecules to perform computation. Reif,
4
and Lagoudakis and LaBean
5
have made further sugges-
tions on this approach. The assembly of DNA-based tiles
into 2D periodic arrays has been reported several times
with a variety of motifs.
6–10
In addition, Rothemund
11
has
performed macroscopic-scale aperiodic self-assembly. In
2000, Mao et al. experimentally implemented the first
algorithmic DNA self-assembly which performed a logi-
cal computation (cumulative XOR) on fixed inputs.
12
In
2003, Yan et al. presented a novel cross shaped DNA
module (four-point–star motif), and formed square grid-
ding structure.
13
Subsequently, Yan et al. also demon-
strated parallel molecular XOR computation using DNA
tiling self-assembly in which a large number of distinct
inputs were simultaneously processed.
14
In 2005, He et al.
created 3-arm motifs called “3-point stars”, that crystallize
beautifully into 30-micron hexagonal lattices.
15
In 2008,
He et al. applied “3-point stars” to further assemble into
tetrahedron, dodecahedron and buckyball.
16
In 2010, Wang
et al. proposed the theoretical models to execute five steps
of a logical (cumulative AND and OR) operations on a
string of binary bits by using DNA triple-crossover (TX)
molecules.
17
Up to now, DNA nanotechnology based on
algorithmic self-assembly of DNA tiles had been devel-
oped at a high speed no matter in constructing theoretical
models or in building the complex nanoarchitectures.
J. Comput. Theor. Nanosci. 2011, Vol. 8, No. 7 1546-1955/2011/8/001/008 doi:10.1166/jctn.2011.1812 1