My research focus on complex physics problems for the understanding of organisms' adaptation and the interactions with their environment. In my presentation, I will present briefly works on chemotactic bacteria at the water-air interface and on the fastest swimming insects, the whirligig beetles, generating gravity-capillary wakes. I will then talk more thoroughly on recent works concerning bubble cavitation in plants and in biomimetic vascular systems.

The ascent of sap in plants relies on the creation of negative pressure (tension) within their vascular networks, rendering them indeed highly susceptible to bubble nucleation and expansion—a phenomenon known as embolism. Embolism is particularly prevalent under drought conditions and is becoming an increasingly critical issue with the intensification of global warming. The complex structure of plant venation networks, compartmentalized into interconnected channels (tracheids or vessel elements), allows plants to mitigate the spread of embolism. Recent advances in imaging techniques have enabled the observation of embolism propagation in plants, revealing complex "stop-and-go" dynamics across varying temporal and spatial scales.

To investigate the appearance of these complex dynamics in compartmentalized systems, bottom-up experimental approaches have been developed using water-swelling hydrogels. I use a pMAA based hydrogel that is exceptionally stiff, and thus capable of withstanding high negative pressures, to micro-fabricate biomimetic leaves with tightly sealed vessel-like microchannels. This system exhibits a multiscale response, combining slow poroelastic water transport and rapid cavitation bubble growth, where inertial, acoustic, and interfacial effects interact. Studying this novel microfluidic device pave the way for identifying the physical parameters governing embolism at negative pressure, providing valuable insights into plant functioning and the engineering of biomimetic vascular networks.