Nanotech Construction Kit

The Nanotech Construction Kit is a new project aimed at improving the understanding of molecular structures at a nanometer-scale level by visualization and interactive manipulation. Our very first prototype is a virtual-reality program allowing the construction of silicate and carbon structures from scratch by assembling them one atom at a time.

In silicate grids, the basic building block is an SiO₄ unit, with the four oxygen atoms arranged around the central silicon atom in the shape of a regular tetrahedron. Two silicate units can connect to each other by their silicon atoms covalently bonding to one shared oxygen atom. Geometrically, this means that two tetrahedra can link at their vertices. Thus, silicate units can form regular crystals with a structure similar to diamond.

Carbon structures have single carbon atoms as basic building blocks. In the structure types of interest, each carbon atom forms three covalent bonds with other carbon atoms; the three bonds form a triangle with the carbon atom at its centroid. Therefore, carbon structural units can be represented as flat triangles connecting at their vertices. Due to their bond angles of 120 degrees, carbon units form flat hexagonal grids with the connectivity of chicken wire. By introducing "flaws" in the grid - either pentagons or heptagons - it is possible to create grids with positive or negative local curvature, respectively. It is also possible to wrap hexagonal grids into cylindrical or conical shapes. Carbon structures of interest include Buckyballs (C-60 Buckminsterfullerene) and Nanotubes (wrapped hexagonal grids of varying circumference). Especially interesting is to understand how to introduce flaws into Nanotubes to make them form branches or junctions.

Figure 1: Two Buckyballs connected by a short piece of Nanotube. Each triangle represents a single carbon atom (located at its center). A movie of a Buckyball being created from scratch, and then being modified, is available for download (MPEG-1 format, 16,437K). The KeckCAVES page contains a video of a user creating and manipulating a Buckyball in a CAVE VR environment (MPEG-1 format, 25MB).

Project Goals

Implement a virtual-reality construction program for nanostructures on an atomic level. This program allows to manipulate single structural units (tetrahedral silicate units or triangular carbon units).
- Implement a simple force field model to simulate the interaction of structural units.
- Implement a selection model to introduce new units into a structure, to move existing structures, and to form and break connections between structures.
Understand how to introduce flaws into a carbon structure to force it to attain a desired shape, e.g., a Nanotube T-juntion.
Implement a higher-level construction program that automatically arranges structural units realizing a shape modelled by a user.
Connect the interactive modelling program with existing full-scale molecular dynamics simulation programs to verify the physical "correctness" of structures built using a simplified interaction model.

Project Status

We implemented the first stage of the project, a virtual-reality manipulation program for nanostructures on the atomic level. It uses a very simple force field model to simulate attraction between structural units' vertices and repulsion between units' centroids. We are currently evaluating whether the simple model leads to physically reasonable structures. We are also trying to understand how deliberate introduction of "flaws" influences the shape of structures, to later generate flaws automatically to create desired shapes.

Pages In This Section

Project Timeline: Detailed overview of work done during the entire run of the project.
Screen Shots: Screen shots of structures created with the Nanotech Construction Kit.
Download: Download page for the current and several older releases of the Nanotech Construction Kit