Arbuckle & Requicha
Self-Assembly and Self-Repair
Self-Assembly and Self-Repair of Arbitrary Shapes by a
Swarm of Reactive Robots: Algorithms and Simulations
D. J. Arbuckle and A. A. G. Requicha
Laboratory for Molecular Robotics
University of Southern California
Self-assembly of active, robotic agents, rather than of passive agents such as molecules,
is an emerging research field that is attracting increasing attention. Active self-assembly
techniques are independent of spatial scale, but they are especially attractive at very small
scales, where alternative construction methods are unavailable or have severe limitations.
Building nanostructures by using swarms of very simple nanorobots is a promising
approach for manufacturing nanoscale devices and systems.
The method described in this paper allows a group of simple, physically identical,
identically programmed and memoryless agents to construct and repair polygonal
approximations to arbitrary structures in the plane. The distributed algorithms presented
here are tolerant of robot failures and of externally-induced disturbances. The structures
are self-healing, and self-replicating to a limited extent. Their components can be re-used
once the structures are no longer needed. A specification of vertices at relative positions,
and the edges between them, is translated by a compiler into reactive rules for assembly
agents. These rules lead to the construction and repair of the specified shape. Simulation
results are presented, which validate the proposed algorithms.
distributed robotics, global-to-local compilation, minimalistic robots,
nanorobots, reactive robots, robot swarms, self-assembly, self-organization, self-repair.
Self-assembly is a process in which autonomous components join themselves to form
more complex structures. Examples of self-assembly are all around (and within) us:
atoms assemble themselves into molecules, supramolecular structures and crystals;
molecules form membranes, organelles and cells; in turn, cells self-assemble into tissues
and entire organisms. In contrast to what happens in nature, non-chemical engineered
systems have not used self-assembly as a manufacturing process until now. (Chemistry
itself is largely based on self-assembly processes.) Interest in self-assembly has been
increasing rapidly over the last decade because it is an inherently parallel process that
seems well-suited to the fabrication of complex structures from the bottom-up, using
micro or nanoscale components. Many manufacturing processes are available at the
macroscale, and self-assembly is not attractive at such scales, except possibly for some
niche applications. However, there are few other promising alternatives for the mass
production of nanosystems.