Редактирование: Open Manufacturing (раздел)

== Molecular Manufacturing ==

[[Molecular Manufacturing]] is the construction of nanoscale or macroscale products with atomic precision, although not necessarily atom by atom. Currently molecular manufacturing is in the realm of some laboratory curiosities, and production of anything larger than a few microns and more complex than the simplest bacterium is decades away. Methods based on [[Scanning Probe Microscope|scanning probes]] can't currently manipulate more than 10-100 atoms in a short timeframe, although [[Molecular Manufacturing#DNA Origami|DNA Origami]] can indirectly shape thousands of atoms into simple 3D structures.

The goal of molecular manufacturing is the construction of a nanofactory: Ideally, a self-replicating machine that is fed a variety of elements in some simple molecules and produces a wide range of [[Molecular Manufacturing#Products|products]] made of multiple materials and machines. There are three paths to this: Biology, scanning probe chemistry and epitaxy. The first is tried and tested, but we don't yet know how to, say, build our own customized ribosomes that build digitally-designed structures. The last two are still in an early stage: Mechanosynthesis is scientifically feasible but is outside of the industry's mainstream and is unlikely to develop soon, epitaxy has more experimental evidence and [[Molecular Manufacturing#Zyvex|Zyvex]] has been working on it under a contract from DARPA.

=== Epitaxy ===

[[Molecular Manufacturing#Patterned Atomic Layer Epitaxy|Patterned Atomic Layer Epitaxy]] (PALE) consists of using a [[Scanning Tunneling Microscope]] on a Hydrogen-terminated Silicon surface to remove individual Hydroge atoms. A variety of cases can be injected into the chamber, where they deposit on the depassivated area of the surface. [http://en.wikipedia.org/wiki/Silylene Silylene] (SiH<sub>2</sub>), in particular, will deposit and add a new layer to the crystal on the depassivated site.

Vertical growth is simple to achieve, but 3D, moving objects can be built using the same method: Grow a bed of Germanium, then grow the Silicon structures on top, and etch away the Ge to remove the structures and machines.

=== Mechanosynthesis ===

Mechanosynthesis is chemical synthesis done by applying mechanical forces and constraints. Ribosmes and atomic force microscopes both do mechanosynthesis of chemical structures through completely different means. Mechanosynthesis is often synonymous with the atom by atom constructiom of crystals and other dry structures, so biological nanomanufacturing has a section of its own.

In mechanosynthesis, an AFM or some kind of nanomanipulator receives instructions from a computer or a record to mechanically move atoms or molecules from a feedstock to a workspace. Contrary to popular criticism, the nanomanipulator is not some kind of magical claw that can grab and drop atoms at will: It is a positionally-controlled, carefully engineered molecule at the end of a crystalline tip that has to be designed specifically for a small set of chemical operations. Different tooltips and mechanical pressures have to be chosen for different feedstock moieties and workspaces and combinations of those.