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Henrik I Christensen
Numerical Analysis and Computing Science
Royal Institute of Technology
SE-100 44 Stockholm, Sweden hic@nada.kth.se
Biological systems live and grow, which are two characteristics that are not truly encompassed by any artefacts developed so far. The c oncept of “living” has a number of consequences in terms of resource limitations, interaction with the environment, adaptation, etc. Growth involves concepts such as neurogenesis, morphogenesis, memory organisation, abstraction, etc. These concepts are fundamental to biological systems and dictate to a certain extent the overall behaviour, morphology, organisation and techniques applied by these entities. Methodologies and technologies that enable construction of artefacts that live and grow would enable a leap in performance for many systems, as we know them today.
The aim of this programme is to study basic methodologies that can pave the way for such artefacts. As part of the programme it is considered essential to use methods from life science as a catalyst/inspiration for creation of new methodologies that allow design, analysis and implementation of artefacts. At the same time it is of interest to re-project developed models back into the domain of life science to provide knowledge of mutual benefit. Methods that simply provide a direct extrapolation from life science or simply take inspiration without any feedback to the domain of origin are thus of limited interest.
Research of particular interest to the programme should thus centre on methods that are biologically plausible, that includes a systems perspective, i.e. methods that are scalable, and involve real-world interaction with the environment. The programme is organised around three major themes: architectural issues, physical instantiation and forms of adaptation. Projects that cover several of these areas and/or their interaction are of particular interest to the programme. Each of the three themes is discussed below.
Architectural issues
- Sensory-motor
- Organisation
- Communication/Interaction
- Drives, emotions, & motivation
- Conflicts/Inconsistencies
- Finite Resources
Mechanisms for adaptation
- evolution
- learning
- development
- neurogenesis
- morphogenesis
Physical Instantiation
- Energetic sufficiency
- Computational substrate
- Advanced materials f.
- sensing
- actuation
- evolvability...
- Body/platform morphology
- Integration

The organisation of systems that live and grow is an essential problem to be considered as it influences memory, learning, sensory-motors facilities, etc. Any living systems must interact with its environment, which in turn requires consideration of aspects of sensing and actuation, and their organisation in terms of basic skills and competences. The sensory-motor system and its morphology (and potential evolution or time) dictate to a certain extent the competence of the full systems, as it defines its interaction. Two different types of interaction should be considered:: physical interaction and communication. Interaction in terms of communication is interesting, as it requires verbalisation of knowledge and engagement in dialogues. Communication can thus be used for communication between systems, but also for interaction with end-users. Living systems are constantly confronted by conflicts and inconsistencies at all levels from sensory input to objectives, which must be considered as part of the design of operational systems. This requires studies of methods for fusion, integration and selection. Finally, drives, emotions and motivation are key characteristics that provide (direct and in-direct) objectives for the acquisition, processing and use of information.
Another essential issue that should be considered is the fact that all living systems have finite resources such as memory, energy, processing power, vocabulary of interaction, etc. Drives and motivation are thus divided between implicit goals for survival and explicit goals related to the interaction with the environment.
The physical instantiation of an artefact is a key issue. One issue here is the selection of materials for the sensory-motor system(s). Sensing and actuation are closely integrated in biological systems, i.e., form and function are tightly intertwined, and it is thus of interest to investigate how the overall design of the physical system can be optimised to accommodate the objectives of an artefacts. This might include use of smart-materials and/or new designs that integrate sensing and actuation. For growing systems it is equally important to consider how the physical system / instantiation can evolve over time. Most biological systems change their morphology over time, yet so far very little progress has been achieved in the design of advanced materials that facilitate similar changes. The interaction between the sensory-motor system and learning, adaptation is also of interest, as there might be a two-way interaction that limits or accelerates growth. The computational substrate used for the implementation of systems is another key problem to be studied. Current computer technology imposes significant constraints in terms of power consumption, complexity, heat dissipation, I/O bandwidth, etc. For systems that grow, use of traditional computer technology might not be a natural choice. Finally, a key issue to be considered as part of the physical instantiation is the energetic sufficiency of the full system. How can the system be designed to optimise use of energy and how can the system acquire / transform materials or interaction into energy for future consumption and what is an efficient medium for storage of energy.
Living and growing systems must deploy learning and evolution to provide adaptation to changes in the environment, to objectives, to evolve beyond simple pre-specification, etc.
Many of the learning and evolutionary mechanisms that are employed today can be considered forms of optimisation. It is not obvious that ‘simple’ optimisation is the best mechanism for adaptation. How can evolutionary methods be changed to speed up adaptation and how can the process be augmented to go beyond optimisation in a given parameter space? It is of particular interest to study systems that go beyond pureprogramming both in terms of operation and adaptation. Another problem is bootstrapping of systems. Most biological systems have evolved over a very large number of generations and it is not obvious that development of artefacts using a similar methodology is a good choice.
Can engineering be used as an efficient basis for bootstrapping of systems, if so what could that tell us about living systems? A related issue is encoding of systems, is information efficiently transfer across generation encoded by the phenotype or can the key information be transferred using a genotype? Such studies might also provide valuable information for life science. For evolution of systems it is of interest to study both morphogenesis and neurogenesis as bases for adaptation in artefacts, but more importantly it is of interest to study the interaction between different mechanisms for adaptation.
Each the three topics outlined above involves very complex and challenging problems. When studied in isolation there is however a risk of loosing the systems perspective. It is thus considered essential that the research within the programme attempts to integrate across the three topics in order to provide a perspective on fully operational artefacts that involve realtime real-world interaction with the environments. It is at the same time essential to find strike a delicate balance between systems and methodologies. The principal focus of the programme is long-term research and preference should thus be given to methodological research rather than specific applications.