Mechanosynthesis

from Wikipedia, the free encyclopedia

Mechanosynthesis is a hypothetical form of chemical synthesis which, in contrast to chemosynthesis , in which molecules in liquids or gases react randomly with one another, could be used specifically to move molecules mechanically. To date, such a system of chemical synthesis has not been developed. However, individual atoms have already been displaced by scanning probe microscopes .

Eric Drexler , a pioneer in the field of molecular nanotechnology , pointed out that mechanosynthesis will be essential for the molecular production of atomically precise nanoscale diamond-like components (very different from today's nanoparticles ) in the long-term goal of nanofactories that he presented .

Diamond Mechanosynthesis

The Nanofactory Collaboration, founded by Robert Freitas and Ralph Merkle in 2000, has specialized in a special type of mechanosynthesis, diamond mechanosynthesis. This should make it possible in the future to mechanically place carbon in particular , but also elements such as hydrogen , boron , nitrogen , oxygen , fluorine , aluminum , silicon , phosphorus , sulfur , chlorine , germanium or tin and to quickly and inexpensively place high-quality macroscopic objects from them to generate. The processes proposed by the collaboration for the production of substances based on diamondoids are hydrogen abstraction, carbon placement and the subsequent addition of hydrogen (hydrogen donation). For the time being, a carbon surface covered with hydrogen is considered in this process. During hydrogen extraction, a tool with a high affinity for binding hydrogen, such as acetylene radicals, extracts some hydrogen atoms from the carbon surface so that the reactive carbon can be used for mechanosynthesis. The carbon can now be precisely displaced and placed during the carbon placement using a specific tool tip (e.g. DCB6Ge). In an article from 2006, Freitas, Merkle and their colleagues report the success of placing a carbon dimer on a C (110) diamond face at 300K and 80K. The DCB6 dimer placement tools have been carefully researched in over 150,000 hours of calculations. In the hydrogen addition, the diamondoids are covered again with hydrogen atoms, which means that they can be less reactive and finally finished. Due to the high reactivity of some of the substances involved, these processes must take place in a vacuum or in a noble gas atmosphere.

Individual evidence

  1. ↑ Noriaki Oyabu, Óscar Custance, Insook Yi, Yasuhiro Sugawara, Seizo Morita: Mechanical Vertical Manipulation of Selected Single Atoms by Soft Nanoindentation Using Near Contact Atomic Force Microscopy . In: Physical Review Letters . tape 90 , no. 17 , May 2, 2003, pp. 176102 , doi : 10.1103 / PhysRevLett.90.176102 .
  2. ^ K. Eric Drexler: Nanosystems: molecular machinery, manufacturing, and computation . Wiley, New York 1992, ISBN 0-471-57547-X .
  3. ↑ Nanofactory Collaboration. In: www.molecularassembler.com. November 16, 2016, accessed January 7, 2017 .
  4. ↑ Diamond Mechanosynthesis. In: www.molecularassembler.com. Retrieved January 7, 2017 (English).
  5. ↑ Ralph C. Merkle, Robert A. Freitas: Theoretical Analysis of a Carbon-Carbon Dimer Placement Tool for Diamond Mechanosynthesis . In: Journal of Nanoscience and Nanotechnology . tape 3 , no. 4 , 2003, p. 319-324 , doi : 10.1166 / jnn . 2003.203 .