• Topic supervised by Bruno LOMBARD (LMA)

By structuring materials, it is possible to control waves and obtain surprising effects: high-resolution lenses, directional antennas, invisibility cloaks, etc. This is the paradigm of metamaterials, a field of research that has been very active since the early 2000s and which promises many technological developments, for example improving Wi-Fi coverage or insulating buildings against seismic waves. However, the properties accessible with these materials also have limits, given by the usual laws of physics. Reciprocity is one of these laws [4]. In the linear regime and without flow, a wave transmitted between two points remains the same when the source and receiver are interchanged. Breaking the reciprocity makes it possible to control the waves in a novel way by making directional band gaps possible. Applications include wave filtering, diode design and logic gates in elastodynamics.(...)

• Topic supervised by Martin BRANDENBOURGER (IRPHE) & Joel MARTHELOT (IUSTI)

Inspired by nature, pneumatic soft robots use vascular networks and external pumps to twist, deform, move and bend in ways that traditional hard robots cannot. So far, these soft robots lack autonomy compared to organisms, which control fluid transport in vascular networks in much more advanced ways. From animals to fungi, one of the most efficient fluid transport mechanism is based on vessels that can actively contract upon local sensing of stimuli. This adaptive fluid transport enables advanced functionalities in organisms such as autonomous locomotion toward objectives. The main goal of the proposed research is to design self-contracting vascular networks to study active solids that deform upon sensing.

• Supervised by Carine GUIVIER-CURIEN (IRPHE), Cécile BARON (IRPHE), Philippe LASAYGUES (LMA)

Bone is a mechanosensitive living tissue subjected to constant remodeling in response to mechanical constraints. Bone remodeling is a skillful balance between the action of bone-forming cells (osteoblasts), and bone-resorbing cells (osteoclasts) orchestrated by bone-mechanosensing cells (osteocytes). However, this natural process is insufficient to address numerous bone disorders such as complex bone fracture or bone cancer, in which bone reconstruction must be assisted. As mechanical waves, ultrasound can provide additional local mechanical stimulation and potentially restore the balance of bone remodeling. (...)

Proteus, one of the oldest cave-dwelling species, exhibits remarkable adaptations on several levels. The objective of this project is to highlight its auditory faculties by carrying out several measurement campaigns at the Theory and Experimental Ecology Station (SETE). Acoustic and vibration measurements will then be carried out on the site. At the same time, simulations will be developed from 3D images taken with a micro-tomograph in order to have a prediction tool.

This project aims to study the unsteadiness of Shock wave boundary layer interactions when the boundary layer does not reattach downstream. Based on an original experimental setup in supersonic flow, previous studies have shown that the separation shock unsteadiness does not exhibit low frequency unlike classical interactions but seems to behave like a low-pass filter and amplifier of the perturbations generated in the subsonic external flow. By means of acoustic control of the subsonic region, the response of the interaction to harmonic disturbances will be explored.