The MesoCardio project, funded by the PEPR MATHS-VivES program, aims to develop models of cardiac muscle contraction at the mesoscale—the intermediate level between molecular motors and tissue mechanics. The proposed Master’s internship (starting April 2026) and PhD thesis (starting October 2026) will be jointly supervised by Matthieu Caruel (MSME, Université Paris-Est Créteil) and Marco Linari and Pasquale Bianco (PhysioLab, University of Florence). Current models overlook the mesoscale organization of sarcomeres, where mechanical and biochemical feedbacks regulate contraction. This project seeks to bridge this gap through a combined theoretical and experimental approach. The PhD will contribute to Work Package 2 (WP2) of MesoCardio, which develops stochastic models of interacting contractile units informed by experimental data. The work includes (1) modeling long-range mechanical interactions within contractile units, (2) conducting experiments on cardiac myocytes and synthetic nanomachines using optical tweezers and X-ray diffraction, and (3) integrating results into mesoscale models incorporating regulatory feedback. The candidate should hold a Master’s in mechanical engineering, biomechanics, or physics, with skills in stochastic modeling, statistical mechanics, and Python programming. The project offers alternating stays in Paris and Florence, fostering close collaboration between modeling and experimental teams.