More than 80% of all animals in the world are arthropods, and amongst them insects are the most diverse and abundant group. Insects inhabit almost all of the world’s ecosystems and show an astonishing variety of different evolutionary adaptations. Hence, insects are often considered to be one of the evolutionary most successful groups of animals.
Part of the insects’ secrets of evolutionary success is their cuticle exoskeleton. After wood, arthropod cuticle is the second most common biological composite material in the world. Cuticle not only exhibits unique biomechanical properties; it is also one of the most versatile biological materials. This makes cuticle an extremely interesting candidate for the design of new bio-inspired composite materials. Surprisingly, despite many decades of research, the fundamental biomechanical properties and principles found in arthropod cuticle are still mostly unknown and the biomimetic potential of cuticle is almost untapped.
Some of the main questions we are currently addressing include:
Although insect cuticle is a very common biological material, very little is known about several of its fundamental biological and biomechanical properties. For example, the capability of insect cuticle to heal and repair damage seems to have been underestimated for a long time.
A particulary interesting aspect of cuticle is the ability of several exoskeleton parts to precisely align the orientation of chitin fibres in alternating layers. The orientation of these layers is presumably controlled by the epidermal cells and affected by ambient light conditions.
In several of our research projects we are investigating the principles of cuticle growth, healing and the mechanisms determining the orientation of chitin fibres. These projects are funded by the Deutsche Forschungsgemeinschaft in collaboration with the Max-Planck-Institute Colloids & Interfaces Potsdam, the University of Dresden, the University of Tübingen and the University of Bremen.
Insects are considered to be the evolutionarily most successful multicellular organisms on earth. An important part of their evolutionary success is their cuticle exoskeleton, which is the most common form of skeletal structures on earth.
Surprisingly, compared to our knowledge about other biological materials our understanding of even basic biomechanical properties of arthropod exoskeletons is almost negligible.
In our group we are using a comprehensive and cross-disciplinary biomechanical approach to answer several key fundamental questions regarding material properties, morphology and histology in insect exoskeletons.
Often a biomechanical analysis of complex structures such as exoskeleton body parts requires a numerical approach.
Together with our collaborators from several other universities we are developing new tools and models to better undestand material properties and function-morphology-correlation of exoskeletal structures.
Most classic engineering joints are based on friction-reducing principles. Several biological joints however are using a different approach. The skeletal structure of the starfish for example allows the organism to maintain a constant body position without the use of external energy. This is achieved by a fascinating combination of small "bone like" structures (ossicles) which are embedded in a unique collagenous matrix.
One of the main goals of the BMBF-funded BIAG project is the analysis, development and construction of such bio-inspired joint structures for aerospace applications.
A weak spot in many protective structures, such as ortheses and prothesis, are the connective elements. In addition, deflection and movement of the structures often lead to unwanted wrinkles and creases, which affect functionality and comfort.
In this BMBF-funded project we analyse exoskeletal joint structures found in arthropods and develop bio-inspired concepts to improve protective exoskeletal structures.
Autonomous and remotely operated underwater vehicles allow us to reach places which have previously been inaccessible and perform complex reparation, exploration and analysis tasks. As their navigation is not infallible, they may cause severe damage to themselves and their often quite fragile surroundings, such as flooded caves, coral reefs or even accompanying divers in case of a collision.
Instead of using rigid encasings, many unicellular organisms such as ciliates, bacteria or algae tolerate impacts. These organisms are only separated from their environment by a single membrane or mostly unsclerotized cell walls. Based on the concept of a “soft exoskeleton” we have developed a biologically inspired, soft and compliant encasing for an underwater vehicle. Our exoskeleton is a versatile and passive solution to protect both the vehicle and its surrounding.