This PhD position at Université Grenoble Alpes focuses on the multiscale hydromechanics of root growth in soils, exploring the complex interactions between plant roots and their surrounding soil environment. The project aims to bridge the gap between biophysics, soil mechanics, and water transfer by developing a unified multiscale and multiphysics modelling framework. The research will be conducted jointly at the 3SR laboratory (Geomechanics group) and the LIPhy laboratory (MC2 group), both located on the Grenoble campus. The 3SR group specializes in hydro-mechanics and micro-mechanics of soils, granular and porous media, and advanced 3D imaging techniques, while the LIPhy group brings expertise in the biophysics of living systems and the dynamics of cell and tissue growth. The PhD student will collaborate closely with five researchers from these labs and benefit from a supportive, interdisciplinary environment. The project is part of the PhD@Tec21 Programme, co-funded by the Marie Skłodowska-Curie COFUND actions, and offers a structured training and networking experience, including potential secondments at international partner institutions. Research will focus on two main axes: (1) the dynamics of water transport from soil to root, including the effects of mucilage secretion and the extension of poromechanical models to account for water uptake; and (2) the multiscale mechanical interactions between roots and soil, modelling how cell-level growth processes influence root elongation and soil deformation. The work will involve advanced numerical simulations (FEM, DEM), analytical modelling, and validation using 4D X-ray and neutron tomography data. Applications span sustainable agriculture, civil engineering (bio-inspired soil stabilization), and robotics (soil-penetrating robots). The position offers a 36-month full-time contract with a competitive salary, full social security, health insurance, and support for visa and registration fees. The ideal candidate will have a Master’s degree in a relevant field, strong skills in mechanics, numerical methods, and interdisciplinary research, and a willingness to engage with both physical and biological sciences. The application deadline is February 28, 2026. For more information and to apply, visit the PhD@Tec21 website or contact the management board.