History of nanotechnology
In 1965, Gordon Moore, one of the founders of Intel Corporation, made the astounding prediction that the number of transistors that could be fit in a given area would double every 18 months for the next ten years. This it did and the phenomenon became known as Moore’s Law. This trend has continued far past the predicted 10 years until this day, going from just over 2000 transistors in the original 4004 processors of 1971 to over 700,000,000 transistors in the Core 2. There has, of course, been a corresponding decrease in the size of individual electronic elements, going from millimeters in the 60’s to hundreds of nanometers in modern circuitry.
At the same time, the chemistry, biochemistry and molecular genetics communities have been moving in the other direction. Over much the same period, it has become possible to direct the synthesis, either in the test tube or in modified living organisms,
Finally, the last quarter of a century has seen tremendous advances in our ability to control and manipulate light. We can generate light pulses as short as a few femtoseconds (1 fs = 10?15 s). Light too has a size and this size is also on the hundred nanometer scale.
Thus now, at the beginning of a new century, three powerful technologies have met on a common scale — the nanoscale — with the promise of revolutionizing both the worlds of electronics and of biology. This new field, which we refer to as biomolecular nanotechnology, holds many possibilities from fundamental research in molecular biology and biophysics to applications in biosensing, biocontrol, bioinformatics, genomics, medicine, computing, information storage and energy conversion.
Historical background
Humans have unwittingly employed nanotechnology for thousands of years, for example in making steel, paintings and in vulcanizing rubber.[1] Each of these processes rely on the properties of stochastically-formed atomic ensembles mere nanometers in size, and are distinguished from chemistry in that they don’t rely on the properties of individual molecules. But the development of the body of concepts now subsumed under the term nanotechnology has been slower.
The first mention of some of the distinguishing concepts in nanotechnology (but predating use of that name) was in 1867 by James Clerk Maxwell when he proposed as a thought experiment a tiny entity known as Maxwell’s Demon able to handle individual molecules.
The first observations and size measurements of nano-particles was made during first decade of 20th century. They are mostly associated with Richard Adolf Zsigmondy who made detail study of gold sols and other nanomaterials with sizes down to 10 nm and less. He published a book in 1914. [2]. He used ultramicroscope that employes dark field method for seeing particles with sizes much less than light wavelength. Zsigmondy was also the first who used nanometer explicitly for characterizing particle size. He determined it as 1/1,000,000 of millimeter. He developed a first system classification based on particle size in nanometer range.
There have been many significant developments during 20th century in characterizing nanomaterials and related phenomena, belonging to the field of interface and colloid science. In the 1920s, Irving Langmuir and Katharine B. Blodgett introduced the concept of a monolayer, a layer of material one molecule thick. Langmuir won a Nobel Prize in chemistry for his work. In early 1950s, Derjaguin and Abrikosova conducted the first measurement of surface forces [3].
There have been many studies of periodic colloidal structures and principles of molecular self-assembly that are overviewed in the paper [4]. There are many other discoveries that serve as scientific basis for the modern nanotechnology can be found in the “Fundamentals of Interface and Colloid Science by H.Lyklema [5].
Conceptual origins
The topic of nanotechnology was again touched upon by “There’s Plenty of Room at the Bottom,” a talk given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, so on down to the needed scale. In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena: gravity would become less important, surface tension and Van der Waals attraction would become more important, etc. This basic idea appears feasible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products. At the meeting, Feynman announced two challenges, and he offered a prize of $1000 for the first individuals to solve each one. The first challenge involved the construction of a nanomotor, which, to Feynman’s surprise, was achieved by November of 1960 by William McLellan. The second challenge involved the possibility of scaling down letters small enough so as to be able to fit the entire Encyclopedia Britannica on the head of a pin; this prize was claimed in 1985 by Tom Newman.[6]
In 1965 Gordon Moore observed that silicon transistors were undergoing a continual process of scaling downward, an observation which was later codified as Moore’s law. Since his observation transistor minimum feature sizes have decreased from 10 micrometers to the 45-65 nm range in 2007; one minimum feature is thus roughly 180 silicon atoms long.
The term “nanotechnology” was first defined by Norio Taniguchi of the Tokyo Science University in a 1974 paper [7] as follows: “‘Nano-technology’ mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or one molecule.” Since that time the definition of nanotechnology has generally been extended to include features as large as 100 nm. Additionally, the idea that nanotechnology embraces structures exhibiting quantum mechanical aspects, such as quantum dots, has further evolved its definition.
Also in 1974 the process of atomic layer deposition, for depositing uniform thin films one atomic layer at a time, was developed and patented by Dr. Tuomo Suntola and co-workers in Finland.
In the 1980s the idea of nanotechnology as deterministic, rather than stochastic, handling of individual atoms and molecules was conceptually explored in depth by Dr. K. Eric Drexler, who promoted the technological significance of nano-scale phenomena and devices through speeches and the books Engines of Creation: The Coming Era of Nanotechnology and Nanosystems: Molecular Machinery, Manufacturing, and Computation, (ISBN 0-471-57518-6). Drexler’s vision of nanotechnology is often called “Molecular Nanotechnology” (MNT) or “molecular manufacturing,” and Drexler at one point proposed the term “zettatech” which never became popular.
In 2004 Richard Jones wrote a book called Soft Machines (nanotechnology and life), is a book about nanotechnology for the general reader, published by Oxford University. In this book he describes radical nanotechnology as a deterministic/mechanistic idea of nano engineered machines that does not take into account the nanoscale challenges such as wetness, stickness, brownian motion, high viscosity (Drexler view). He also explains what is soft nanotechnology or more appropriatelly biomimetic nanotechnology which is the way forward, if not the best , to design functional nanodevices that can cope with all the problems at nanoscale. One can think of soft nanotechnology as the development of nanomachines that uses the lessons learned from biology on how things work, chemistry to precisely engineer such devices and stochastic physics to model the system and its natural processes in detail.