Molecular Nanotechnology Presented By, Gopal Bharathwaj 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Agenda What is molecular manufacturing ? Comparison between various design and modeling techniques. Introduction to molecular machines. Sufficiency of current modeling methods. A family of six degree of freedom positional devices. Conclusion 9/16/2018 Molecular Nanotechnology

Molecular manufacturing Manufactured products are made from atoms. Rearranging the atoms in an already existing product helps us to develop new products. Today’s manufacturing methods are very crude at the molecular level. We will be able to snap together the fundamental building block of nature easily, inexpensively and in almost all the arrangements that we desire. 9/16/2018 Molecular Nanotechnology

Various design and modeling techniques Chemical Vapor Deposition (CVD) Molecular Mechanics Ab initio quantum analysis 9/16/2018 Molecular Nanotechnology

Carbon Vapor Deposition (CVD) Hydrogen abstraction during CVD involves a radical reaction between atomic hydrogen and the gas with H bonded to carbon on the surface producing H2. 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Molecular Mechanics Modeling of the positions of the nuclei of individual atoms. The individual nuclei are usually treated as point masses. And the potential energy E, is a function of distance between the nuclei (r). 9/16/2018 Molecular Nanotechnology

Example of Molecular Mechanics Consider the hydrogen atom. It consists of two nuclei. The function E(r) depends on two major factors: Inter nuclei repulsion. Interaction between the nuclei and the electrons. Hence the two hydrogen nuclei will adopt a position so as to minimize E(r). 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Example (contd…) As the inter nuclei distance (r) increases. The potential energy of the system increases. Nuclei experience a restoring force that returns them to their original distance. On the other hand, as r decreases The two nuclei are pushed closer together and The restoring force pushes them farther apart. 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Example (contd…) Knowing the positions r1,r2,…rn of N nuclei E(r1,r2,…rn ) gives the potential energy of the system. If we know the potential energy as a function of the nuclear positions Determine the forces acting on the individual nuclei. Compute the evolution of their positions over time. The particular values of E at particular points are determined by Schrodinger’s equation. 9/16/2018 Molecular Nanotechnology

Ab initio quantum analysis Process that uses the mechanical positioning of reactive species to control chemical reactions, by either providing activation energy or selecting between alternative reaction pathways allowing us to construct a wide range of complex molecular structures. 9/16/2018 Molecular Nanotechnology

Ab initio quantum analysis (contd…) Applying position control to reactions will require the tools to have certain properties Have proper chemical properties. Be relatively small to reduce steric interactions with the work piece. Capable of being chemically and mechanically stable under thermal motions and strains induced during positioning. Be bound to a system that can transfer forces and torques to reactive portions of the tool. Be selective between alternative reactions. Be easily made. 9/16/2018 Molecular Nanotechnology

Ab initio quantum analysis (contd…) Method of creating the radical. The obvious approaches are… The C-H bond problem. 9/16/2018 Molecular Nanotechnology

Ab initio quantum analysis (contd…) How to solve the C-H bond problem? Attack by two weak radical strategy. Photo exhibiting technique 9/16/2018 Molecular Nanotechnology

Ab initio quantum analysis (contd…) R1-H-R2 HF GVBCI-SCF CCCI DCCI HF*SD CI GVB*SD CI H-H-Ha 24.3 9.9 10.3 10.5(9.6)c 10.3(10.3) CH3-H-CH3 34.9 27.8 29.8 17.5 22.5(19.5) 20.4(18.8) H-H-CCH 11.6 8.0 5.4 0.8 4.5(3.2) 3.3(2.7) CH3-H-CCH 14.6 8.6 10.2 -2.9bb 4.2(2.0) 2.2(1.3) (CH3)3C-H-CCH 11.0 5.9 -7.0 0.45(-2.78)   C6H6-H-CCH 18.3 12.0 14.3 -0.7 7.7(4.1) HCC-H-CCH 30.0 22.9 24.1 17.0(13.7) 14.6(12.9) 9/16/2018 Molecular Nanotechnology

Sufficiency of current modeling methods It is quite possible to adequately model the behavior of molecular machines that satisfy two constraints They are built from sufficiently stable parts. The synthesis of the parts is done by using positionally controlled reactions. 9/16/2018 Molecular Nanotechnology

A new family of six degree of freedom positional devices Stewart Platform The double tripod The crank Five strut crank 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Stewart Platform 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology The double Tripod 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology The Crank 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Five Strut Crank 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Conclusion Derive detailed description of the behavior of the proposed systems. Substantially reduce the development time for the complex molecular machines. It is possible to debate how long it will be before we achieve robust molecular manufacturing capability. We will get there sooner if we develop and make intelligent use of molecular design tools and computational models. 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology References http://www.zyvex.com/nanotech/CDAarticle.html http://www.nanozine.com/ http://www.zyvex.com/nanotech/compChemLinks.html http://www.socialtechnologies.com http://www.zyvex.com/nanotech/6dof http://www.zyvex.com/nanotech/Habs/paper.html 9/16/2018 Molecular Nanotechnology

Molecular Nanotechnology Questions??? 9/16/2018 Molecular Nanotechnology