Programmable Self-Assembly: Constructing Global Shape using Biologically-inspire

Item

Title
en_US Programmable Self-Assembly: Constructing Global Shape using Biologically-inspire
Creator
en_US Nagpal, Radhika
Date
2004-10-20T20:28:28Z
Date Available
2004-10-20T20:28:28Z
Date Issued
en_US 2001-06-01
Identifier
en_US AITR-2001-008
Abstract
en_US In this thesis I present a language for instructing a sheet of identically-programmed, flexible, autonomous agents (``cells'') to assemble themselves into a predetermined global shape, using local interactions. The global shape is described as a folding construction on a continuous sheet, using a set of axioms from paper-folding (origami). I provide a means of automatically deriving the cell program, executed by all cells, from the global shape description. With this language, a wide variety of global shapes and patterns can be synthesized, using only local interactions between identically-programmed cells. Examples include flat layered shapes, all plane Euclidean constructions, and a variety of tessellation patterns. In contrast to approaches based on cellular automata or evolution, the cell program is directly derived from the global shape description and is composed from a small number of biologically-inspired primitives: gradients, neighborhood query, polarity inversion, cell-to-cell contact and flexible folding. The cell programs are robust, without relying on regular cell placement, global coordinates, or synchronous operation and can tolerate a small amount of random cell death. I show that an average cell neighborhood of 15 is sufficient to reliably self-assemble complex shapes and geometric patterns on randomly distributed cells. The language provides many insights into the relationship between local and global descriptions of behavior, such as the advantage of constructive languages, mechanisms for achieving global robustness, and mechanisms for achieving scale-independent shapes from a single cell program. The language suggests a mechanism by which many related shapes can be created by the same cell program, in the manner of D'Arcy Thompson's famous coordinate transformations. The thesis illuminates how complex morphology and pattern can emerge from local interactions, and how one can engineer robust self-assembly.
Extent
en_US 118 p.
27221557 bytes
1541086 bytes
Format
application/postscript
application/pdf
Language
en_US
Relation
en_US AITR-2001-008
Subject
en_US AI
en_US self-organisation
en_US multi agent
en_US developmental biology
en_US amorphous computing