MEchanics of integrated and artificial Biological Systems

The MEBS theme revolves around 4 complementary axes, all centered on the mechanics of integrated and artificial biological systems.

On the one hand, we study mechanical transduction processes from the macroscopic scale to the molecular and cellular scales, combining biomimetic approaches with a simple biological system.

  • At the macroscopic scale, we study the human tactile perception of complex fluids (emulsions, suspensions) by the tongue-palate system. On this subject, we are collaborating with the Nestlé Group and its Research Center based in Lausanne, Switzerland, and have developed a device that reproduces the functioning of the oral cavity. In particular, we seek to better understand how the surface structure of the tongue, in the form of papillae, participates in the mechanical filtering of tactile information before any coding by the central nervous system.
  • At molecular and cellular scales, we seek to better understand how the subcutaneous mechanoreceptors (present in humans under the surface of the skin of the fingers, but also in the tongue ...) and which determines in particular their response properties frequency. To this end, we develop model mechanoreceptors consisting of a lipid membrane (of the Droplet Interface Bilayers type) decorated with mechanosensitive ion channels, or assemblies of model cells connected together by these same channels, stimulated under controlled mechanical excitation conditions. For this purpose, we use TX-TL type in-vitro expression techniques for mechanosensitive proteins.
  • We also explore mechanotransduction processes in a mechanosensitive eukaryotic microorganism, paramecium, by developing behavioral experiments (optical tracking of trajectories) coupled with measurements of ionic flux across the membrane, by calcium imaging and electrophysiology. It is more particularly to understand how the behavioral response of the paramecium depends on the geometrical and mechanical properties of obstacles that it encounters.
  • We are also studying recently a new subject dedicated to the mechanics of biomimetic tissue models. The aim is to study the elastoplastic response of emulsions subjected to controlled mechanical disturbances, in order to better understand the physical bases underlying the collective remodeling of biological tissues, especially during morphogenesis. These emulsions, which are the analog of biological tissues, are formed of oil droplets in an aqueous medium, whose surface can be functionalized to mimic cell-cell adhesion.