Productive nanosystems
Encyclopedia
The Technology Roadmap for Productive Nanosystems defines "productive nanosystems" as functional nanometer-scale system
s that make atom
ically-specified structures
and devices
under programmatic
control, i.e. they perform manufacturing
to atomic precision
.
Present-day technologies are limited in various ways. Large atomically precise structures exist, in the form of crystal
s. Complex
3D
structures exist in the form of polymer
s such as DNA
and protein
s. It is also possible to build very small atomically precise structures using scanning probe microscopy
to manipulate
individual atoms or small groups of atoms. But it is not yet possible to combine components in a systematic way to build larger, more complex systems.
Principles of physics and examples from nature both suggest that it will be possible to extend atomically precise fabrication to more complex products of larger size, involving a wider range of material
s. An example of progress in this direction would be Christian Schafmeister's work on bis-peptide
s.
, one of the architects of the USA's National Nanotechnology Initiative, has proposed four states of nanotechnology that seem to parallel the technical progress of the Industrial Revolution, of which productive nanosystems is the most advanced.
1. Passive nanostructures - nanoparticles and nanotubes that provide added strength, electrical and thermal conductivity, toughness, hydrophilic/phobic and/or other properties the emerge from their nanoscale structure.
2. Active nanodevices - nanostructures that change states in order to transform energy, information, and/or to perform useful functions. There is some debate about whether or not state-of-the art integrated circuits qualify here, since they operate despite emergent nanoscale properties, not because of them. Therefore, the argument goes, they don't qualify as "novel" nanoscale properties, even though the devices themselves are between one and a hundred nanometers.
3. Complex nanomachines - the assembly of different nanodevices into a nanosystem to accomplish a complex function. Some would argue that Zettl
's machines fit in this category; others argue that modern microprocessors and FPGAs also fit.
4. Systems of nanosystems/Productive nanosystems - these will be complex nanosystems that produce atomically precise parts for other nanosystems, not necessarily using novel nanoscale-emergent properties, but well-understood fundamentals of manufacturing. Because of the discrete (i.e. atomic) nature of matter and the possibility of exponential growth, this stage is seen as the basis of another industrial revolution. There are currently many different approaches to building productive nanosystems: including top-down approaches like Patterned atomic layer epitaxy
and Diamondoid
Mechanosynthesis
. There are also bottom-up approaches like DNA Origami
and Bis-peptide
Synthesis .
A fifth step, info/bio/nano convergence, was added later by Roco. This is the convergence of the three most revolutionary technologies, since every living thing is made up of atoms and information.
System
System is a set of interacting or interdependent components forming an integrated whole....
s that make atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
ically-specified structures
Chemical structure
A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...
and devices
Machine
A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...
under programmatic
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
control, i.e. they perform manufacturing
Manufacturing
Manufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...
to atomic precision
Accuracy and precision
In the fields of science, engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements of a quantity to that quantity's actual value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which...
.
Present-day technologies are limited in various ways. Large atomically precise structures exist, in the form of crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s. Complex
Complexity
In general usage, complexity tends to be used to characterize something with many parts in intricate arrangement. The study of these complex linkages is the main goal of complex systems theory. In science there are at this time a number of approaches to characterizing complexity, many of which are...
3D
Dimension
In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...
structures exist in the form of polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
s such as DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s. It is also possible to build very small atomically precise structures using scanning probe microscopy
Scanning probe microscopy
Scanning Probe Microscopy is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. An image of the surface is obtained by mechanically moving the probe in a raster scan of the specimen, line by line, and recording the probe-surface interaction as a...
to manipulate
Donald Eigler
Donald M. Eigler is a physicist and IBM Fellow at the IBM Almaden Research Center. On September 28, 1989 he achieved a landmark in humankind’s ability to build small structures by demonstrating the ability to manipulate individual atoms with atomic-scale precision...
individual atoms or small groups of atoms. But it is not yet possible to combine components in a systematic way to build larger, more complex systems.
Principles of physics and examples from nature both suggest that it will be possible to extend atomically precise fabrication to more complex products of larger size, involving a wider range of material
Material
Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to...
s. An example of progress in this direction would be Christian Schafmeister's work on bis-peptide
Bis-peptide
Bis-peptides are analogues of peptides, but consist of bis-amino acids, which bear two carboxyl groups and two amino groups. The connection of specific bis-amino acids leads to the formation of bis-peptides with well-defined molecular shape, which is of great interest for designing...
s.
Stages of progress in nanotechnology
Mihail RocoMihail Roco
Mihail Roco is the chair of the US National Science and Technology Council subcommittee on Nanoscale Science, Engineering and Technology , and is Senior Advisor for Nanotechnology at the National Science Foundation...
, one of the architects of the USA's National Nanotechnology Initiative, has proposed four states of nanotechnology that seem to parallel the technical progress of the Industrial Revolution, of which productive nanosystems is the most advanced.
1. Passive nanostructures - nanoparticles and nanotubes that provide added strength, electrical and thermal conductivity, toughness, hydrophilic/phobic and/or other properties the emerge from their nanoscale structure.
2. Active nanodevices - nanostructures that change states in order to transform energy, information, and/or to perform useful functions. There is some debate about whether or not state-of-the art integrated circuits qualify here, since they operate despite emergent nanoscale properties, not because of them. Therefore, the argument goes, they don't qualify as "novel" nanoscale properties, even though the devices themselves are between one and a hundred nanometers.
3. Complex nanomachines - the assembly of different nanodevices into a nanosystem to accomplish a complex function. Some would argue that Zettl
Alex Zettl
Alex Zettl is an American professor of experimental condensed-matter physics. His research involving the properties of novel materials have produced significant advances in the field.-Biography:...
's machines fit in this category; others argue that modern microprocessors and FPGAs also fit.
4. Systems of nanosystems/Productive nanosystems - these will be complex nanosystems that produce atomically precise parts for other nanosystems, not necessarily using novel nanoscale-emergent properties, but well-understood fundamentals of manufacturing. Because of the discrete (i.e. atomic) nature of matter and the possibility of exponential growth, this stage is seen as the basis of another industrial revolution. There are currently many different approaches to building productive nanosystems: including top-down approaches like Patterned atomic layer epitaxy
Atomic layer epitaxy
Atomic layer epitaxy or Atomic Layer Chemical Vapor Deposition , now more generally called Atomic Layer Deposition , is a specialized form of epitaxy that typically deposit alternating monolayers of two elements onto a substrate. The crystal lattice structure achieved is thin, uniform, and...
and Diamondoid
Diamondoid
A diamondoid, in the context of building materials for nanotechnology components, most generally refers to structures that resemble diamond in a broad sense: namely, strong, stiff structures containing dense, 3-D networks of covalent bonds, formed chiefly from first and second row atoms with a...
Mechanosynthesis
Mechanosynthesis
Mechanosynthesis is any chemical synthesis in which reaction outcomes are determined by the use of mechanical constraints to direct reactive molecules to specific molecular sites.-Introduction:...
. There are also bottom-up approaches like DNA Origami
DNA origami
DNA origami is the nanoscale folding of DNA to create arbitrary two and three dimensional shapes at the nanoscale. The specificity of the interactions between complementary base pairs make DNA a useful construction material through design of its base sequences...
and Bis-peptide
Bis-peptide
Bis-peptides are analogues of peptides, but consist of bis-amino acids, which bear two carboxyl groups and two amino groups. The connection of specific bis-amino acids leads to the formation of bis-peptides with well-defined molecular shape, which is of great interest for designing...
Synthesis .
A fifth step, info/bio/nano convergence, was added later by Roco. This is the convergence of the three most revolutionary technologies, since every living thing is made up of atoms and information.