In nature, order, complexity and patterns are formed spontaneously through bottom up organization of specific local interactions. A process called self-assembly. This section groups EPFL’s research projects that use these principals, especially at the molecular level, to create complex structures and materials.
Organic nanowires are model systems for the investigation of charge transport in organic semiconductors under nanoscopic confinement, and may serve as potential building blocks for integrated circuits in the future. However, reliable structure-property relationships between the molecular parameters, the intermolecular π–π interactions, the nature of the charge carriers, and macroscopic transport properties are scarce. We have developed a reliable model system for the self-assembly of various chromophores into well-defined nanowires with excellent π–π overlap of the chromophores. These nanowires exhibit an unprecedented light-induced “self-doping”, resulting in exceptionally high charge densities and band-like transport properties.
Our research activities focus on conjugates of synthetic polymers and biologically-inspired peptide sequences. The peptide sequences are adapted from protein structures and direct the structure formation of the synthetic polymer. The use of such peptide sequences offers several unique advantages. First of all, due to the very specific folding and organization properties of the peptide sequences, they allow the organization of synthetic polymers in complex, hierarchically-organized structures that are very difficult to generate otherwise. Secondly, the structure and properties of peptide – synthetic hybrid block copolymers can be manipulated by single amino acid “mutations” in the peptide segments (see Strucutre page). The peptide sequence of the hybrid block copolymers cannot only be used to drive structure formation, but can also be used to encode specific functionalities. This is a subject of ongoing research efforts.
Structural Self-assembly of Origami Robots, Robogamis
While Origami, the traditional Japanese art of paper folding, is primarily known for its artistic significance, many of its components can be found in nature. From insect wings to different types of leaves, organisms take advantage of the ability to create thin and lightweight structures by folding quasi-two-dimensional elements in distinct patterns. At the Reconfigurable Robotics Lab, RRL, we are developing robots that mimic and enhance the benefits of Origami found in nature. Our robots incorporate quasi-two-dimensional smart structures with embedded actuation, sensing, control, and communication, allowing them to change both shape and functionality according to the task at hand. By automating these structural transformations and functional reconfigurations, we are creating versatile robotic systems that are compact for storage and transportation and, when deployed, can self-assemble into lightweight, three-dimensional tools.