SAMBA Lab at SISSA

SAMBA is a multidisciplinary laboratory run at SISSA-International School for Advanced Studies through a collaboration between the Applied Mathematics and the Cognitive Neuroscience groups. We combine theory, numerical simulations, and experiments to study:

  • the motility of biological systems (e.g., Euglenids) and of model, soft robots;
  • the fracture behaviour of biological tissues and polymer gels;
  • the bioinspired morphing in soft active materials;
  • the mechanics of tactile perception in rats as mediated by whiskers;
  • the tactile perception in robotic hands.

Below is a short description of our scientific activities. Please follow the publications link in the menu bar for more informations.


 


As an example of our experimental activity on soft robotics, we show a prototype robotic crawler exploiting frictional, directional interactions with a groove-textured substrate. A shape-memory alloy actuator drives the reciprocal shape-changes of the system, whereas the directionality of the interactions arises from the inclination of flexible, elastic bristles. Our studies on motility also comprise biological systems such as snakes, gastropods, and unicellular micro-swimmers (e.g., Euglenids).

 


Natural thin structures typically exhibit non-trivial shapes which are determined by growth or by swelling in response to environmental stimuli. Remarkably, their mechanics has profound implications on function. Taking inspiration from these natural systems, we engineer shape-morphing structures made of soft active materials, such as stimuli-responsive polymer gels. We also use elastic bilayers as a model system to explore the interplay between mechanics and geometry in determining shape.

 


As regards fracture mechanics, our activity focusses on the study of biological tissues and polymer gels. These are remarkable examples of soft active materials, i.e., natural or synthetic systems that undergo large deformations in response to external, non-mechanical stimuli. Specifically, we aim at understanding the mechanisms and dissipative processes that contribute to the macroscopic fracture toughness of such complex materials (e.g., multiple cracking in epithelial monolayers, poroelastic toughening in gels).

 


Visualization and tracking of the facial whiskers is required in an increasing number of rodent studies. However, this task is challenging for multiple reasons, primary among them the low contrast of the whisker against its background. We propose a fluorescent dye method suitable for visualization of one or more rat whiskers, which makes the dyed whisker easily visible against a dark background. The coloring does not influence the behavioral performance of rats, nor does it affect the whiskers’ mechanical properties.