Page 11 - Nanotechnology an introduction

of Section 1.1.2.
Table 1.2 Table of the relative importance (ranked by numbers of occurrences of words in the titles of papers presented at the Nano2009 Conference in Houston, Texas) of nanotechnology terms and applications
Rank Term Number of occurrences
1 Carbon, CNT 151
2 Nanoparticle, nanocrystal 138
3 Energy 96
4 (Nano)material 92
5 Nanotube 82
6 (Nano)composite 79
7 (Bio)sensor 55
8 Water 45
9 Device 33
10 Nanowire 33
11 Assembly 31
12 Silicon 30
13 Zinc (oxide) 26
14 Titanium (oxide) 25
15 Quantum 24
16 Silica 21
17 Phage 20
18 Bio 19
19 Photovoltaic 15
20 Nanorod 8
21 Graphene 7
22 Nanopore 7
23 Silver 7
A number of inferences can be drawn from this table, including the preeminence of carbon as a nanomaterial, the nanoparticle as a nano-object,
and energy, composites (materials) and sensors as applications. Interestingly, “water” features highly on the list. The reasons for this will be
apparent from reading Section 3.8.
A very simple (albeit privative) ostensive definition of nanotechnology is “If you can see it (including with the aid of an optical microscope), it's not
nano”, referring to the fact that any object below 100 nm in size is below the Abbe limit for optical resolution using any visible wavelength (equation
5.2). A nanoplate, however, would only be invisible if oriented exactly parallel to the line of sight.
1.3. A Brief History of Nanotechnology
Reference is often made to a lecture given by Richard Feynman in 1959 at Caltech [56]. Entitled “There's Plenty of Room at the Bottom”, it
expounds his vision of machines making the components for smaller machines (a familiar enough operation at the macroscale), themselves
capable of making the components for yet smaller machines, and simply continuing the sequence until the atomic realm is reached. Offering a prize
of $1000 for the first person to build a working electric motor with an overall size not exceeding 1/64th of an inch, Feynman was dismayed when not
long afterwards a student, William McLellan, presented him with a laboriously hand-assembled (i.e., using the technique of the watchmaker) electric
motor of conventional design that nevertheless met the specified criteria.

A similar idea was proposed at around the same time by Marvin Minsky: “Clearly it is possible to have complex machines the size of a flea;
probably one can have them the size of bacterial cells … consider contemporary efforts towards constructing small fast computers. The main line of
attack is concentrated on “printing” or evaporation through masks. This is surely attractive; in one operation one can print thousands of elements.
But an alternative, equally attractive, has been ignored. Imagine small machines fabricating small elements at kilocycle rates. (The speed of small
mechanical devices is extremely high.) Again, one can hope to make thousands of elements per second. But the generality of the mechanical
approach is much greater since there are many structures that do not lend themselves easily to laminar mask construction”[118]. One wonders
whether Feynman and Minsky had previously read Robert A. Heinlein's short story “Waldo”, which introduces this idea (it was published in the
August 1942 issue of “Astounding” magazine under the pseudonym Anson MacDonald).
Here we find the germ of the idea of the assembler, a concept later elaborated by Eric Drexler. The assembler is a universal nanoscale assembling
machine, capable not only of making nanostructured materials, but also other machines (including copies of itself). The first assembler would have
to be laboriously built atom-by-atom, but once it was working numbers could evidently grow exponentially, and when a large number became
available, universal manufacturing capability, hence the nano-era, would have truly arrived (see also Chapter 8).

However, the idea of a minute device intervening at the level of elementary particles was conceived almost a hundred years earlier by James Clerk
Maxwell when he conceived his “demon” for selectively allowing molecules to pass through a door, thereby entangling physics with information.
Perhaps Maxwell should be considered as the real father of nanotechnology. The demon was described in Maxwell's Theory of Heat first published
in 1871, but had already been mentioned in earlier correspondence of his.

1.3.1. Ultraprecision Engineering

It could well be said that the history of technological advance is the history of ever finer tolerances in machining metals and other materials. A
classic example is the steam engine: James Watt's high-pressure machine that paved the way for the technology to move from a cumbersome and
rather inefficient means of pumping water out of mines to an industrially useful and even self-propelling technology was only possible once
machining tolerance had improved to enable pistons to slide within cylinders without leaking.

An approach to the nanoscale seemingly quite different from the Heinlein–Feynman–Minsky–Drexler vision of assemblers starts from the
microscopic world of precision engineering, progressively scaling down to ultraprecision engineering (Figure 1.2). The word “nanotechnology” was
itself coined by Norio Taniguchi in 1974 to describe the lower limit of this process [159]. He referred to “atomic bit machining”.