AN INTRODUCTION TO NANOCOMPUTING - Bio-Inspired and Nanoscale Integrated Computing - page 2

end of the microcomputing era and the beginning of the nanocomputing era.
Nanocomputing could be fundamentally different from microcomputing: indivi-
dual particles could play a significant role; quantum effects enter the game much
more directly. Even though Feynman's vision has been partially realized with such
tiny transistors, researchers are only beginning to explore the fundamental
questions: How small can we make computers? How would such computers
work? How can we embrace quantum mechanics for computation? What
applications are possible with nanocomputing that were not possible with
microcomputing? We will explore these questions throughout the topic.
In this introductory chapter, we will give a brief overview of devices,
paradigms, and applications of nanocomputing. Of course, we cannot include
all existing ideas about nanocomputing in the introduction, or even in the entire
topic. Instead, we aim to inspire the reader with a variety of ideas that appear
commonly in nanocomputing research. We will first define computing and
nanocomputing and provide some historical context of the microcomputing era.
The limitations of today's microcomputers motivate a discussion of nanoscale
devices and paradigms, many of which are detailed in later chapters. We then
consider two major fields that can greatly benefit from nanocomputing: biology
and neurology.
1.2. WHAT IS NANOCOMPUTING?
Computing is the representation and manipulation of information. Computer
games, surfing the Internet, solving complex math equations, and even verbal
communication are examples of computing. While we certainly compute using our
own thinking power, it is often more useful to create a machine that computes on
its own so we can use it to enhance our daily lives. Indeed, our world has become
dependent on machines that automatically compute for us. These ''computers''
are used for entertainment, education, safety, and a vast number of other
applications, all of which require manipulation of abstract information.
To build a computing machine, abstract data must eventually be represented
by something that physically exists. For example, digital states (such as 1's and 0's)
can be represented as high and low voltages on a wire. Similarly, manipulations of
abstract data, such as adding two numbers, must eventually be performed by a
physical phenomenon that affects the data. Therefore, to explore the world of
computing, we must ask the most fundamental question: How can we use physics
to represent and manipulate abstract information?
Directly or indirectly, researchers from all over the world are exploring this
fundamental question. This endeavor spans across several disciplines, including
mathematics, computer science, physics, chemistry, and biology. Throughout this
topic, there are many examples of how physics can be used for computation; some
of these ideas may eventually lead to more powerful computers.
Nanocomputing can be interpreted literally as computing at the nanometer
scale. It is generally agreed that the terms nanotechnology, nanocomputing, and