Morphological Computation and Morphological Control: Steps Toward a Formal Theory and Applications

Abstract

Morphological computation can be loosely defined as the exploitation of the shape, material properties, and physical dynamics of a physical system to improve the efficiency of a computation. Morphological control is the application of morphological computing to a control task. In its theoretical part, this article sharpens and extends these definitions by suggesting new formalized definitions and identifying areas in which the definitions we propose are still inadequate. We go on to describe three ongoing studies, in which we are applying morphological control to problems in medicine and in chemistry. The first involves an inflatable support system for patients with impaired movement, and is based on macroscopic physics and concepts already tested in robotics. The two other case studies (self-assembly of chemical microreactors; models of induced cell repair in radio-oncology) describe processes and devices on the micrometer scale, in which the emergent dynamics of the underlying physical system (e.g., phase transitions) are dominated by stochastic processes such as diffusion.

Simple or Complex Bodies? Trade-offs in Exploiting Body Morphology for Control

“…Following the dynamical system's perspective, [14] provide an illustration of the possible goals of the design process: (1) To design the physical dynamical system such that desired regions of the state space have attracting properties. Then it is sufficient to use a simple control signal that will bring the system to the basins of attraction of individual stable points that correspond to target behaviors.…”

“…The modeling and optimization of more complicated morphologies-like compliant structures-is nevertheless an active research topic (e.g., Wang [50] and other work by the author). The second point of Füchslin et al [14]-achieving "morphological programmability" by constructing a dynamical system with a parametrized attractor landscape-remains even more challenging though.…”

“…Instead, many of them are concerned with exploiting morphological properties to simplify a control task. This has been labeled "morphological control" in [14]; "mechanical control" could be an alternative label. Developing controllers that exploit a given morphology is only a first step.…”

Formalizing Modularization and Data Hiding in Synthetic Biology

“…In Reller [60] and later in Fuchslin et al [27], an approach was presented in which compartments assemble into a reaction environment, an artificial tissue. This tissue then hosts a second assembly step, namely the assembly of branched polymers.…”

Guided Self-Organization in a Dynamic Embodied System Based on Attractor Selection Mechanism

“…However, they are also affected by both the ecological niche where the system is physically embedded and the morphology, i.e., shape, size and material properties, of the system. In other words, behaviors of embodied systems must be seen as results of self-organization among the internal control structure, the body and the environment [21][22][23][24]. In fact, the emergence of distinguishable behaviors depends on the interaction among these three components [24].…”