Stéphane Bordas has been leading research in the field of theoretical and applied mechanics since his PhD began, in 1999. His PhD, under the supervision of Professor Brian Moran, at Northwestern University focused on three-dimensional fracture and biofilm growth simulations using the extended finite element method (XFEM).

Stéphane's team, known as the Legato Team ( has been active at the interface between applied mathematics and data and computational sciences. Legato has focused on geometrically unfitted methods, where the finite element mesh does not conform to the boundary of the domain, with applications ranging from fracture mechanics to brain cell metabolism.

The major contributions of his team are considered to be: Goal-oriented a posteriori error estimates for enriched finite element methods with applications; Real-time mesh adaptation for large deformations in biomechanics; Geometry Independent Field Approximation (GIFT); Reduced order models in fracture mechanics; Adaptive multi-scale methods for fracture; Uncertainty quantification and model selection in mechanics.

His work is implemented in commercial codes, e.g. Morfeocrack and he is a cofounder and Chief Scientific Officer of Ariana Tech (, a risk-management company incorporated in Luxembourg in 2020.