We have organized two subsequent discussion meetings approaching scientific challenges in the advancement of molecular materials research: The focus is on the transition from understanding and predicting properties towards the rational design of material systems that qualify for being complex and adaptive.
These are not simple materials, but systems that possess properties, which so far are only known for living organisms or man-controlled machines like robots. We believe it is very timely to discuss together with physicists, chemists and also interested researchers from life science the state of the art and the particular challenges given by the gap between assembly of molecules to materials and developing molecular systems that can actively interact with feedback mechanisms and have the ability to perform work.
With this ambitious goal in mind, a small group of 40 scientists met in Ringberg Castle at lake ‘Tegernsee’ in December 2014. Please have a look at ‘Part I Ringberg 2014’ to learn more about the contents and participants of this first meeting.
We would now like to invite you to join the second meeting in Vaalsbroek Castle to participate in the discussions. The idea is to extend the focus towards multistability, programming and feedback mechanisms, but also to complement the concepts by more new chemistries.
The symposium will start on Sunday, October 11 in the late afternoon and end on Thursday, October 15 after lunchtime. It will address a community of about 130 participants.
Lately, material sciences are heading towards rational design and synthesis of materials with increasing structural complexity. Keywords are “hierarchically organized structures“ and “bioinspired materials“. Challenged by Nature‘s principles of molecular self-assembly and self-regulation, research is directed towards mastering hierarchical equilibrium and non-equilibrium organization on length and time scales from molecular dimensions via sub-structured nano-objects, to materials with entirely new properties. Different from Nature‘s evolution such goals are sought in short time through rational understanding of the structural diversity and dynamic variations that are enabled by the complex interplay of covalent bonding, hydrogen bonding and weak short and long range intermolecular forces. Ultimately these developments focus on the advancement from structural and functional materials to material systems with active properties, approaching the abilities of living systems such as self-assembly versus self-organization, responsiveness, self-healing, self-cleaning, and locomotion.
The capability for active adaptation and interactivity is one of the most profound challenges of today’s materials research and will significantly advance the evolution of structural materials via functional to intelligent ones. Carefully designed molecular components provide and complex, well-balanced interactions govern structure and dynamics of such molecular components, often imitating the ideal of biological systems.
New challenges need to be addressed to exceed the passive functionalities of existing materials and approach next generation, active molecular materials. This includes the integration of internal energy conversion systems to allow active functions, switchable material properties, hierarchical self-assembly, the application of memory effects, as well as development of internal and external feedback mechanisms.
This discussion conference will bring together a group of world-leading scientists in this interdisciplinary field of research to discuss and foster exchange of concepts and ideas. Ample time will be allocated to discussions in an informal setting, including organized leisure activities and evening poster sessions.
It appears obvious that such a new class of synthetic molecular materials will comprise many characteristics of complex adaptive systems that are constituted from totally different agents and which are subject of topical mathematical and physical studies, e.g.:
- Complex systems consist of distinct units that interact with each other. Hence we have to design these units purposefully (molecules, nanoparticles).
- We have to focus on the design and development of emergent properties, i.e., the properties of the system as a whole cannot be deduced from the properties of the single components, but are controlled by the interaction of the components. A hierarchical organization is an approach that can generate emergent behavior and the structural response to an external trigger will yield new properties.
- Complex systems are often metastable. Hence we need to consider and exploit the fact, that their properties depend on the conditioning path yielding hysteresis effects.
- We have to focus on nonlinear relations in the interaction between components, that cause cooperativity and synergistic effects. Due to the coupling between components a change in one or several components or small disturbances and differences in the starting configuration can affect the whole system strongly.
- Complex behavior is usually observed for open systems in contact with their environment. They exist in a thermodynamic gradient and dissipate energy. This can cause self-organization.
- Feed back loops and self-regulation: The effects of an element‘s behavior are fed back to it in such a way that the element itself is altered.
For the development of a road map towards complex adaptive material systems and as central issues of this workshop we have identified three key points:
1. Interdisciplinary research approaches must be advanced within the field of macromolecular science and it‘s allied disciplines within the chemical, physical, materials and biological sciences. New inter- and trans-disciplinarity is already established to quite some extent. Polymer Science and Colloid Science are on the way to reunite and the emergence of the nanoscience progressively overcomes demarcations between physics, biology, chemistry and engineering sciences.
2. Entirely new engineering approaches need to be developed for the efficient manufacturing of complex materials. Complex structures found in nature are mostly grown slowly and their development is adjusted by feedback mechanisms. Technologies for similarly complex structures are still in their infancy. Examples are the layer-by-layer- and new 3D-lithography technologies, like multi-photon polymerization.
So far, production processes, that exploit self-assembly and self-organization for the formation of functional structures are mostly limited to coatings and thin films or fibers, e.g., thermo- and electro-responsive liquid crystalline films.
3. Researchers should dispose of a fundamental understanding of complex systems and the rules of their formation, functionality and activity. This is a rather new and by itself extremely challenging field of science. It focuses on the collective behavior of interacting components, and how the system interacts with its environment. The field cuts across very different disciplines, as well as engineering, biology, molecular and social systems formed out of people. The brain formed out of neurons, the weather formed out of air flows or the stock market are all examples for complex systems.