Nanotechnology and Functional Materials for Engineers

Yaser Dahman

• Publisher: Elsevier
• Year: 2017
• Print ISBN: 9780323512565
• eBook ISBN: 9780323524667
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Nanotechnology and Functional Materials for Engineers focuses on key essentials and examples across the spectrum of nanomaterials as applied by engineers, including nanosensors, smart nanomaterials, nanopolymers, and nanotubes. Chapters cover their synthesis and characteristics, production methods, and applications, with specific sections exploring nanoelectronics and electro-optic nanotechnology, nanostructures, and nanodevices.This book is a valuable resource for interdisciplinary researchers who want to learn more about how nanomaterials are used in different types of engineering, including electrical, chemical, and biomedical.- Offers in-depth information on a variety of nanomaterials and how they are used for different engineering applications- Provides an overview of current research and suggests how this will impact future applications- Explores how the unique properties of different nanomaterials make them particularly suitable for specific applications

Chapter 1

An Introduction to Nanotechnology*

Abstract

Nanotechnology can be defined as the process of creating functional materials, devices, and systems through control of matter on an atomic and molecular scale. Fundamental properties found at the nanoscale include melting temperature, thermal conductivity, charge capacity, electronic conduction, tensile strength, and even color of a material. There are two approaches for performing research within the field of nanotechnology: the top–down approach and the bottom–up approach. At present time, the practice of nanotechnology embraces both stochastic approaches and deterministic approaches wherein single molecules are manipulated on the substrate surface through the use of scanning tunneling microscope and atomic force microscope. Some examples of using nanotechnology in the areas of computing, quantum computing, and communication devices can be seen in semiconductors, thin film storage, and magnetic random access memory. Nanoscale medicine has made significant breakthroughs in the applications of biocompatible materials, diagnostics, and treatments. Nanotechnology has made a great emergence in the field of imaging with contrast agents including biodegradable polymer-based nanogels/nanospheres/nanoemulsions, carbon nanotubes, dendrimers, etc. Moreover, nanotechnology can be used in targeted drug delivery for cancer treatment and in noninvasive vaccinations such as DNA-based. The future outlook of nanotechnology trends shows the stages of nanotechnology discovery and integration of nanosystems and the converging of technologies.

Keywords

Top–down; bottom–up; atomic force microscope; STM; imaging; noninvasive vaccination; silicon transistors; Norio Taniguchi; stochastic

1.1 Definition

There is no fixed definition for nanotechnology that is precise and clear, because it is still a growing field with many areas that are still unknown. In 1999, the definition of nanotechnology set out from the National Nanotechnology Initiative (NNI) is given from an article (Roco, 1999):

Nanotechnology is the ability to control and restructure the matter at the atomic and molecular levels in the range of approximately 1–100 nm, and exploiting the distinct properties and phenomena at that scale as compared to those associated with single atoms or molecules or bulk behaviour. The aim is to create materials, devices, and systems with fundamentally new properties and functions by engineering their small structure. This is the ultimate frontier to economically change materials properties, and the most efficient length scale for manufacturing and molecular medicine. The same principles and tools are applicable to different areas of relevance and may help establish a unifying platform for science, engineering, and technology at the nanoscale. The transition from single atoms or molecules behaviour to collective behaviour of atomic and molecular assemblies is encountered in nature, and nanotechnology exploits this natural threshold.

We can see that the definition is very long and detailed. Over a decade ago, there were not as many nanotechnology discoveries as there are today, and it can be shown by the change in definition. In 2010, the International Standardization Organization (ISO) Technical Committee 229 on nanotechnologies (ISO, 2010) issued a definition of nanotechnology:

The application of scientific knowledge to manipulate and control matter in the nanoscale range to make use of size- and structure-dependent properties and phenomena distinct from those at smaller or larger scales.

The more recent definition is precise and clear. The elements chosen in the definition are the manipulation and control of matter on the nanoscale and the creation of materials and devices using the smaller scale. Basically, we can say that nanotechnology is the creation of functional materials, devices, and systems through control of matter on an atomic molecular scale.

1.2 Introduction

One of the most important reasons for studying nanotechnology is that it is on this nanoscale that the fundamental physical and chemical properties of a material and system are determined. These fundamental properties include its melting temperature, thermal conductivity, charge capacity, electronic conduction, tensile strength, and even color. This creates an interesting situation in which a material may have one set of properties on the large scale and a different set of properties on the nanoscale. The reason for this is that there is continuous modification of material characteristics with its changing size. The onset of nanotechnology illustrates how small our understanding is on the detailed processes by which molecules organize and assemble themselves. This leads into the exciting field of the construction of quantum devices and the operation of complex nanostructured systems. It is this change in properties based on material size that lead to exploration of a wide new array of different possibilities that were once never conceived, such as opaque substances that become transparent (copper), stable material that turns combustible (aluminum), solids that turn into liquids at room temperature (gold), and insulators that become conductors (silicon). One of the more intriguing discoveries is gold which is chemically stable on the large scale, but when examined on the nanoscale, it can serve as a very potent chemical catalyst. Much of the interest in nanotechnology is due to the fact that the characteristics at the nanoscale greatly differ from the larger scale with which we are familiar.

Another interesting characteristic of nanotechnology is that it is not limited solely to one small field of science. The implications of changing the physical and chemical properties of a material can influence many existing fields of science and technology (Fig. 1.1). It is nearly impossible to completely understand the potential of nanotechnology on the future of humanity. Here is a list of only a few of potential beneficial uses for nanotechnology (Fig. 1.2):

Vastly improved delivery and control characteristics as medicines move down to the nanoscale.

Greatly increased printing accuracy as nanoparticles are employed which have properties of both dyes and pigments.

Vastly improved lasers and magnetic heads as increased control of layer thickness is moved toward the nanoscale.

Figure 1.1 Nanotechnology involves different fields of science and engineering.

Figure 1.2 There is a variety of applications to nanotechnology.

There are two approaches for performing research within the field of nanotechnology: the top–down approach and the bottom–up approach. The top–down approach is characterized by a material being processed in bulk which is shaped into the finished product. In this approach, the positioning of individual atoms is not controlled during operation. Since no specific order in atoms can be achieved, this process results in defects and impurities (Forrest, 2008). Micropatterning techniques, such as photolithography and inkjet printing, belong to this category. Photolithography is a process of micro-fabrication employing the selective removal of a thin film from the surface of the sample. The bottom–up approach on the other hand describes a manufacturing process in which it is possible to control individual atoms. Bottom–up approaches rely on either (1) the chemical properties of a single molecule to self-organize or self-assembly in some useful configuration or (2) positional assembly. Self-assembly offers huge potential economic advantages. The creation of nanocomposites with organic molecules can be performed by depositing organic molecules to ultrasmall particles or ultrathin man-made layered structures (Arnall, 2003) (Fig. 1.3).

Figure 1.3 The types of fabrication of nanomaterials. From AIST (2007). http://www.aist.go.jp/index_en.html.

1.3 History

Although nanotechnology is a relatively recent development in scientific research, the development of the central concepts has happened over a longer period of time. We have unknowingly been using nanotechnology for thousands of years through applications such as making steel, paintings, and in vulcanized rubbers. The development of the body of concepts that we understand to be called nanotechnology however has only recently turned up. The first mention of some of the distinguishing concepts in nanotechnology appeared in 1867 by James Clerk Maxwell. He proposed a thorough experiment known as Maxwell’s demon which is a tiny entity able to handle individual molecules. The first observations on the nanoscale took pl...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Biography
• Preface
• Chapter 1. An Introduction to Nanotechnology
• Chapter 2. Generic Methodologies for Characterization
• Chapter 3. Smart Nanomaterials
• Chapter 4. Nanosensors
• Chapter 5. Nanoparticles
• Chapter 6. Nanopolymers
• Chapter 7. Nanotubes
• Chapter 8. Nanoshells
• Chapter 9. Electronic and Electro-Optic Nanotechnology
• Chapter 10. Self-Assembling Nanostructures
• Chapter 11. Nanomedicine
• References
• Index