The opening mechanism of the capsules of Aizoaceae

Plants are able to adapt the geometry of their organs and tissue  properties to cope with external and internal stresses and to actuate  organ movement. All movements due to moisture changes in cell walls  are controlled by the architecture of stiff cellulose fibrils embedded  in a swellable matrix. Notably these actuating movements function  without the need of an active metabolism, very unlike molecular motors  in the human muscle, for example. This makes the humidity-based  actuation systems in plants particularly interesting for biomimetic  materials. The project aims to analyze the hierarchical structuring  and the deformation mechanisms of the capsules in Aizoaceae, which  impressively unfold after wetting. For this the nanostructural  switches inside the fruits have to be identified which upon actuation  result in large macroscopic deformations of the capsule. We expect to  derive concepts for the design of biomimetic materials by a better  understanding of the general principles by which active gels can be  directed in their swelling behaviour and by identifying the  sophisticated hierarchical organization that translates nanostructural  deformation into macroscopic movement.

Duration: June 2009 to June 2011

Contact: Dr. Friedrich Ditsch

Leader: Prof. Dr. Christoph Neinhuis

Collaborational partners:
Dr. habil. Ingo Burgert & Dr. Matt J. Harrington, Max-Planck-Institute  of Colloids und Interfaces, Potsdam

Funded by the Deutsche Forschungsgemeinschaft (DFG) within the  priority program (SPP) 1420  Biomimetic Materials Research:  Functionality by Hierarchical Structuring of Materials