Publications

2026

• Biointegration of a partially decellularized tracheal scaffold in a porcine model - preliminary results
  
  • Vigouroux Augustin
  • Bonnin Yannis
  • Gendron Nicolas
  • Kellouche Sabrina
  • Agniel Rémy
  • Bruneval Patrick
  • Balvay Daniel
  • Allain Jean-Marc
  • Chhun Stéphanie
  • Kempf Hervé
  • Hugon Romain
  • Devriese Magali
  • Sansac Caroline
  • Larghero Jérôme
  • Arakelian Lousineh
  • Thierry Briac
  Scientific Reports, Nature Publishing Group, 2026, 16 (1), pp.10121. Some pediatric tracheal pathologies remain therapeutic dead ends for which current palliative strategies are fraught with serious complications. With the aim of a tracheal replacement, our team has previously developed and patented a clinical grade partially decellularized trachea (PDT) from porcine tracheas. The aim of this work was to study and compare the biointegration mechanisms of this PDT in vivo, in a pig cervical muscle, with or without immunosuppressant. The secondary objective was to evaluate the optimal maturation time of the PDT in this heterotopic position. In total, 11 female Large White/Landrace pigs, weighing between 50 and 70 kg were included in this study. The mean age of the animals at the implantation was 4.8 months. The PDTs were implanted in a cervical muscle of pigs for either 28 days, with or without cyclosporin A treatment, or for 56 days without immunosuppression. Histological evaluation showed very good PDT biointegration, characterized by neovascularization and fibroblast colonization, and no detectabale infection. Additionally, tissue and blood analyses showed no signs of graft rejection or surrounding tissue necrosis. Immunosuppression did not show any superiority in terms of biointegration after 28 days of treatment. After 56 days of implantation, a more significant degradation of the cartilage. Therefore, the optimal condition for PDT maturation proved to be 28 days, without immunosuppression. (10.1038/s41598-026-37823-1)
  DOI : 10.1038/s41598-026-37823-1
• Rapid estimation of microstructure using infrared imaging and solidification modeling in wire-laser directed energy deposition
  
  • Dollé Quentin
  • Bréhier Michèle
  • Berté Emmanuel
  • Witz Jean-Francois
  • Tournier Christophe
  • El Bartali Ahmed
  • Weisz-Patrault Daniel
  , 2026. The widespread deployment of Directed Energy Deposition Additive Manufacturing is limited by the lack of control over the produced material depending on process parameters: in particular, the microstructure resulting from rapid solidification. While cost-efficient numerical simulations have been developed to predict temperature evolution and microstructure, their reliability hinges on high-quality experimental validation. This study first addresses this challenge by introducing a simple and cost-effective infrared measurement procedure that combines a single-band camera and a dual-band pyrometer to quantitatively measure temperature fields during wire-laser DED. To do so, the apparent emissivity field was identified and found to be highly heterogeneous due to localized cover gas and oxidation. In addition, to enable rapid microstructure estimation, fast computational procedures are proposed to (i) calculate the thermal gradient field using Fast Fourier Transform, and (ii) simulate solidification in the melt pool, including competitive growth between columnar dendritic grains, using a recent Voronoi tessellation-based model. The computation time is compatible with the development of an online monitoring procedure. The resulting microstructure predictions were validated against Electron Backscatter Diffraction measurements, demonstrating excellent qualitative agreement. This work validates the proposed approach as a promising tool for closed-loop control of microstructure during DED.
• One- and Two-Photon Polymerization of Solvent- and Filler-Free Aromatic Organic Precursors: Toward 3D-Printed Semiconducting Microstructures
  
  • Noè Camilla
  • Laroui Sami
  • Zucchi Gaël
  • Bodelot Laurence
  ACS Applied Engineering Materials, ACS, 2026, 4 (2), pp.926-935. Over the past decades, a great deal of attention has been dedicated toward developing semiconductive polymers (SP), which are now considered as a critical class of photoactive and electroactive materials. However, the processing of many SPs involves the use of solvents, leading to the fabrication of samples with limited shapes, mostly flat 2D thin films. To develop 3D-shaped materials with potential semiconducting properties, this work tackles the development of solvent-and filler-free resins for the fabrication via additive manufacturing of microscale organic semiconductors. Two molecular liquids based on electron-rich carbazole and triarylamine units are used to formulate photoresists. The successful reactivity of the formulations was investigated, both at the macroscopic scale (one-photon polymerization through UV curing) and at the microscopic scale (two-photon polymerization (2PP) via direct laser writing), with Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Subsequently, the thermal properties of the macroscopic samples were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Optimization of the printing parameters for 2PP led to the elaboration of 3D micrometer-scale samples whose morphology was assessed by scanning electron microscopy (SEM). Finally, electrical measurements revealed a semiconducting behavior as the samples were found to conduct current after p-doping with iodine. (10.1021/acsaenm.5c01101)
  DOI : 10.1021/acsaenm.5c01101
• Mean stress effects and energy-based modeling of fatigue behavior in artificially cemented rock-like materials under cyclic loading
  
  • Darsanj Solmaz
  • Emami Tabrizi Mehrdad
  • Constantinescu Andrei
  Bulletin of Engineering Geology and the Environment, Springer Verlag, 2026, 85 (2), pp.113. (10.1007/s10064-025-04757-3)
  DOI : 10.1007/s10064-025-04757-3
• Additive Manufacturing repair of damaged parts of a reusable launcher
  
  • Girault Florian
  , 2026. The objective of the thesis is to answer the problem encountered by CNES in the repair of reusable launch vehicle parts. The particularity comes from the fact that the chemical nature of the alloys constituting the candidate parts does not allow theuse of the Additive Manufacturing processes conventionally used, which imply a passage in liquid phase ofthe material and induce, in addition to the problems of segregation and cracking which can be controlled, an evaporation of certain elements of alloy. This work studies, in the case of aerospace aluminium alloys, the effect on microstructures and mechanical behaviourof different alternative repair options. In particular,the use of so-called solid-phase friction-stir processessuch as AFSD (Additive Friction Stir Deposition) is investigated. The analyses performed are multi-scale,examining the quality of the deposited material, the interface with the damaged part, and the effects of the repair on the part.
• Finite element modelling for the reproduction of dynamic OCE measurements in the cornea
  
  • Merlini Giulia
  • Imperiale Sébastien
  • Allain Jean-Marc
  Journal of the Mechanics and Physics of Solids, Elsevier, 2026, 206, pp.106363. Recent advances in dynamic elastography, particularly through optical coherence tomography combined with transient excitations have enabled rapid, localized, and non-invasive mechanical data acquisition of the cornea. This dataopens the path to early-detection of pathologies and more accurate treatment. However, the analysis of the wave propagation is a complex mechanical problem: the cornea is a structure under pressure, with non-linear material behavior. Thus, computational analysis are needed to extract mechanical parameters from the data. In this study, we present a time-dependent finite element model for the reproduction of transient shear wave elastographic measurements in the cornea. The mechanical problem consists in a smallamplitude wave propagating in the cornea, largely deformed by intraocular pressure in physiological conditions. The model accounts for anisotropic, hyperelastic, and incompressible behavior of the cornea, as well as its accurate geometry, and the preloaded condition. We have implemented two different numerical approaches to solve first the static non-linear inflation of the cornea and then the linear wave propagation problem to reproduce the measurements. We investigate the impact of material anisotropy and prestress on wave propagation and demonstrate that intraocular pressure critically influences shear wave velocity. Additionally, by introducing a localized mechanical defect to simulate a pathological defect, we show that simulated shear wave can detect and quantify mechanical weaknesses, suggesting potential as a diagnostic tool to assess corneal health. (10.1016/j.jmps.2025.106363)
  DOI : 10.1016/j.jmps.2025.106363
• A stationarity principle generating effective boundary conditions for second-order homogenization
  
  • Thbaut Manon
  • Audoly Basile
  • Lestringant Claire
  Journal of Elasticity, Springer Verlag, 2026, 158 (1), pp.15. We derive an effective model for a periodic chain of linearly-elastic springs, achieving second-order accuracy in the scale separation parameter $\varepsilon \ll 1$. The chain has finite length and is made up of springs connecting both nearest- and next-nearest-neighbors: it serves as a one-dimensional prototype for higher-order periodic homogenization problems with boundaries. This type of problem has been approached by inserting two-scale expansions into the equations of equilibrium in the bulk and by matching them with boundary-layer solutions. We explore an alternative method operating at the energy level, bypassing the cumbersome matching procedure. We start from an ansatz of the microscopic displacement accounting for both boundary layers and for small-scale fluctuations in the bulk, and insert it into the discrete energy. This yields a continuous energy functional depending on the macroscopic displacement $u$, in the form of a series expansion in powers of $\varepsilon$. We call it a {\tmem{pseudo-energy}} $\Phi_{\varepsilon} [u]$ as it is not positive when truncated at order~$\varepsilon^2$. The boundary terms in the pseudo-energy account for boundary layers in an effective way. By making the pseudo-energy stationary order by order in $\varepsilon$, we derive the homogenized equations of equilibrium along with effective boundary conditions. We provide quantitative validation showing that the effective model is correct to second order. We point out the special form of the effective higher-order tractions, which has been overlooked in strain-gradient theories proposed so far. (10.1007/s10659-026-10190-8)
  DOI : 10.1007/s10659-026-10190-8
• SCAR : a self-consistent recurrent cell for real-time finite strain elastoplastic simulations
  
  • Lesueur Louis
  • Weisz-Patrault Daniel
  • Thorin Anders
  , 2026. Complex fabrication and forming processes operating under finite strains could benefit significantly from optimization loops of process parameters, which are often hindered by the prohibitive computational costs of process modeling. Neural networks present a promising solution to derive fast and accurate surrogate models, thereby enabling such optimizations. Furthermore, many processes involve substantial inherent variability, and hence often require manual process control. Neural networks could also provide real-time predictions that would greatly assist in decision-making. Although recursive neural networks have been applied in mechanics, their use in modeling elastoplastic behavior at finite strains remains underexplored. This paper introduces a new family of self-consistent recurrent cells, referred to as SCAR. These cells are specifically designed to address history-dependent problems, such as elastoplasticity, and ensure compliance with key properties required for such applications. To evaluate the SCAR cells, a generic architecture named PlastiNN, featuring a spatially resolved neural decoder, is employed. This approach results in faster training times and more accurate predictions in comparison to commonly used architectures. Additionally, PlastiNN can accommodate a series of successive loads on a workpiece, which is critical for most fabrication and forming processes. The effectiveness of this strategy is demonstrated by comparing SCAR cells to other recurrent cells within the PlastiNN architecture through a comprehensive benchmark including two datasets of 1D and 3D simulations, ranging from challenging toy applications to more realistic industrial test cases. Results highlight the superiority of the proposed recurrent neural network architecture for modeling elastic-plastic behavior at finite strains in engineering processes.
• Assessment of Human Corneal Biomechanical Properties After Refractive Surgery With Inflation Test Using Optical Coherence Tomography
  
  • Memmi Benjamin
  • Wu Qian
  • Borderie Vincent
  • Allain Jean-Marc
  Journal of Refractive Surgery, Slack, 2026, 42 (1), pp.64-70. The incidence of myopia is currently increasing worldwide. It is becoming a significant public health issue, with billions of people (ie, 49.8% of the world population) estimated to be affected by this condition by 2050. Refractive surgery is a corneal surgery that treats myopia by modifying the shape of the cornea. Photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) are three mainstay refractive surgeries worldwide. Recent advances, specifically in the understanding of the biomechanical properties of the cornea and its response to diseases and surgical interventions, have significantly improved the safety and surgical outcomes of corneal refractive surgery, whose popularity and demand continue to grow worldwide. However, iatrogenic keratectasia resulting from the deterioration in corneal biomechanics caused by surgical interventions, although rare, remains a global concern. In vivo biomechanical evaluation, enabled by clinical imaging systems such as the ORA (Reichert Technologies) and the Corvis ST (Oculus Optikgeräte GmbH), has significantly improved the risk profiling of patients for iatrogenic keratectasia. (10.3928/1081597x-20251202-03)
  DOI : 10.3928/1081597x-20251202-03
• Micro-Poro-Mechanical Modeling of The Lung Parenchyma: Theoretical Modeling and Parameters Identification
  
  • Manoochehrtayebi Mahdi
  • Genet Martin
  • Bel-Brunon Aline
  Journal of Biomechanical Engineering, American Society of Mechanical Engineers, 2026, 148 (1), pp.BIO-25-1063. Micro-poro-mechanical approaches can be employed to simulate the behavior of porous media, such as lung parenchyma, with respect to their microscopic morphological and mechanical features. In this work, we propose a general micromechanical framework to describe the behavior of a porous hyperelastic material in large strains, including surface tension, and adapt its parameters to reproduce lung parenchyma behavior. We illustrate the method on a 2D periodic microstructure. The modeling framework is adaptable to any microstructure and any combination of stress, strain and pressure loadings.The identification of the model parameters in the context of lung parenchyma, based on existing experimental morphological and pressure-volume data, is performed sequentially. 12 parameters related to morphology, alveolar wall constitutive behavior and surface tension are calibrated to reproduce pressure-volume curves in various conditions, for a porosity in the unloaded state set to Φf0 =63%. The calibrated alveolar diameter is Dalv = 54 μm. The identifiability of the Neohookean and Ogden-Ciarlet-Geymonat hyperelastic potential parameters is studied; their values are β1 = 94.3 Pa, β2 = 16.9 Pa, β3 = 619 Pa and α = 3.154. The hysteretic response of lung to pressure is reproduced thanks to the formulation of a surface-dependent surface tension. This work paves the way for a better understanding of the relationship between microscopic features and the macroscopic response of lung, in healthy and pathological conditions. Further experimental investigations could help confirming the ranges of parameters obtained in this study. (10.1115/1.4070036)
  DOI : 10.1115/1.4070036
• Community challenge towards consensus on characterization of biological tissue: C4Bio’s first findings
  
  • Famaey Nele
  • Fehervary Heleen
  • Lafon Yoann
  • Akyildiz Ali
  • Dreesen Silke
  • Bruyère-Garnier Karine
  • Allain Jean-Marc
  • Alloisio Marta
  • Aparici-Gil Alejandro
  • Catalano Chiara
  • Chassagne Fanette
  • Chokhandre Snehal
  • Crevits Kimberly
  • Crielaard Hanneke
  • Cunnane Eoghan
  • Cunnane Connor
  • de Leener Karen
  • Desai Amisha
  • Driessen Rob
  • Erdemir Ahmet
  • Eskandari Mona
  • Evans Sam
  • Gasser Christian
  • Gebhardt Marc
  • Glasmacher Birgit
  • Holzapfel Gerhard
  • Isasi Mikel
  • Jennings Louise
  • Kurz Sascha
  • Leal-Marin Sara
  • Lecomte Pauline
  • Morch Annie
  • Mulvihill John
  • Nemavhola Fulufhelo
  • Pandelani Thanyani
  • Pasta Salvatore
  • Peña Estefania
  • Pierrat Baptiste
  • Ploeg Heidi-Lynn
  • Polzer Stanislav
  • Rausch Manuel
  • Schwarz David
  • Screen Hazel
  • Sherifova Selda
  • Sommer Gerhard
  • Wang Shengzhang
  • Walsh Darragh
  • Yadav Deepesh
  • Marchal Thierry
  • Geris Liesbet
  Journal of Biomechanics, Elsevier, 2026, 194, pp.113021. This study investigates methodological variability across various expert laboratories worldwide, with regards to characterizing the mechanical properties of biological tissues. Two testing rounds were conducted on the specific use case of uniaxial tensile testing of porcine aorta. In the first round, 24 labs were invited to apply their established methods to assess inter-laboratory variability. This revealed significant methodological diversity and associated variability in the stress–stretch results, underscoring the necessity for a standardized approach. In the second round, a consensus protocol was collaboratively developed and adopted by 19 labs in an attempt to minimize variability. This involved standardized sample preparation and uniformity in testing protocol, including the use of a common cutting and thickness measurement tool. Despite protocol harmonization, significant variability persisted across labs, which could not be solely attributed to inherent biological differences in tissue samples. These results illustrate the challenges in unifying testing methods across different research settings, underlining the necessity for further refinement of testing practices. Enhancing consistency in biomechanical experiments is pivotal when comparing results across studies, as well as when using the resulting material properties for in silico simulations in medical research. (10.1016/j.jbiomech.2025.113021)
  DOI : 10.1016/j.jbiomech.2025.113021
• 3D finite element investigation of hyperelastic foam behavior. II. Influence of microstructure in closed- and open-cell foams
  
  • Merlette Thomas
  • Diani Julie
  Mechanics of Materials, Elsevier, 2026, 221, pp.105774. This study investigates the impact of microstructure parameters on the mechanical behavior of random soft polymer foams using numerical simulations on representative volume elements under both infinitesimal and finite strain conditions. Two types of closed-cell foams are considered, Voronoi-based microstructures, which reproduce foams obtained via autoclave processes, and microstructures with rounded pores and curved wall with heterogeneous wall thicknesses, as observed in pressure injection molding foams. Open-cell foams are also analyzed by removing elements from the center toward the edges of Voronoi cells. Under infinitesimal strain, simple shear, uniaxial tension, and hydrostatic tension tests are applied to directly compare the linear shear, Young’s, and bulk moduli, providing a more comprehensive approach than most studies, which typically rely solely on uniaxial tension and simple shear to characterize linear elastic behavior of these heterogeneous materials. In the finite strain regime, severe uniaxial compression and large uniaxial tension tests provide a complete and contrasting assessment of the impact of microstructures. While wall thickness heterogeneities induce severe wall folding, affecting local strain distribution in the matrix, their macroscopic impact is negligible or of secondary order under uniaxial compression but becomes significant under uniaxial tension. For open-cell foams, as expected, they exhibit weaker behavior than closed-cell foams, with their mechanical response strongly dependent on the degree of openness. (10.1016/j.mechmat.2026.105774)
  DOI : 10.1016/j.mechmat.2026.105774
• Stability analysis of a new curl-based full field reconstruction method in 2D isotropic nearly-incompressible elasticity
  
  • Chibli Nagham
  • Genet Martin
  • Imperiale Sébastien
  Inverse Problems, IOP Publishing, 2026. In time-harmonic elastography, the shear modulus is typically inferred from full field displacement data by solving an inverse problem based on the time-harmonic elastodynamic equation. In this paper, we focus on nearly incompressible media, which pose robustness challenges, especially in the presence of noisy data. Restricting ourselves to 2D and considering an isotropic, linearly deforming medium, we reformulate the problem as a non-autonomous hyperbolic system and, through theoretical analysis, establish existence, uniqueness, and stability of the inverse problem. To ensure robustness with noisy data, we propose a least-squares approach with regularization. The convergence properties of the method are verified numerically using in silico data.
• A new surrogate microstructure generator for porous materials with applications to the buffer layer of TRISO nuclear fuel particles
  
  • Eisenhardt Philipp
  • Khristenko Ustim
  • Wohlmuth Barbara
  • Constantinescu Andrei
  Journal of Nuclear Materials, Elsevier, 2026, 624, pp.156498. We present a surrogate material model for generating microstructure samples reproducing the morphology of the real material. The generator is based on Gaussian random fields, with a Matérn kernel and a topological support field defined through ellipsoidal inclusions clustered by a random walk algorithm. We identify the surrogate model parameters by minimizing misfits in a list of statistical and geometrical descriptors of the material microstructure. To demonstrate the effectiveness of the method for porous nuclear materials, we apply the generator to the buffer layer of Tristructural Isotropic Nuclear Fuel (TRISO) particles. This part has been shown to be a failure sensitive part of TRISO nuclear fuel and our generator is optimized with respect to a publicly available dataset of the buffer layer FIB-SEM tomography measured by a team of researchers from University of Wisconsin at Madison and Oak Ridge National Laboratory. We evaluate the performance by applying mechanical modeling with problems of linear elastic homogenization and linear elastic brittle fracture material properties and comparing the behaviour of the dataset microstructure and the surrogate microstructure. This shows good agreement between the dataset microstructure and the generated microstructures over a large range of porosities. (10.1016/j.jnucmat.2026.156498)
  DOI : 10.1016/j.jnucmat.2026.156498
• Memory and recovery effects in the strain hardening regime of glassy polymers: theory and simulations
  
  • Merlette Thomas C.
  • Hem Jérôme
  • Crauste-Thibierge Caroline
  • Ciliberto Sergio
  • Bikard Jerome
  • Long Didier R.
  Soft Matter, Royal Society of Chemistry, 2026, 22, pp.967-978. (10.1039/d5sm01077b)
  DOI : 10.1039/d5sm01077b
• Multifunctional architectured and composite materials by design: geometry, experiments, coupling and multiscale challenges
  
  • Danas Kostas
  • Auffray Nicolas
  • Dirrenberger Justin
  • Réthoré Julien
  • Sebald Gaël
  • Le Duigou Antoine
  • Mbiakop Armel
  • Lacroix Thierry
  Mechanics & Industry, EDP Sciences, 2026, 27, pp.35. Architectured materials–also referred to as architected materials in the literature–have experienced significant growth over the past two decades, largely driven by rapid advances in fabrication techniques at the mesoscopic scale, ranging from a few hundred microns to several centimeters. These technological developments have stimulated parallel progress in numerical and theoretical modeling, considerably expanding the accessible design space. Beyond the classical stiffness-to-weight paradigm, attention has extended to properties such as yield strength, buckling behavior, and multifunctional responses, including thermo-electro-magneto-mechanical couplings. The concept of mesoscopic architecture has further been combined with composite materials whose microstructure lies at the micron scale, resulting in systems governed by three intrinsic length scales: micro-, meso-, and macroscales. This multiscale interplay offers an even broader and more versatile design landscape. Although research activity in architectured materials is thriving at the laboratory scale, their large-scale industrial deployment and integration into everyday applications remain in early stages. Despite their remarkable ability to achieve properties rarely found in natural materials, challenges related to design methodologies, manufacturability, scalability, and reliable numerical analysis still need to be addressed. This article provides a broad perspective on the field, with particular emphasis on the contributions o f the French research community over the past 15 years. (10.1051/meca/2026031)
  DOI : 10.1051/meca/2026031
• Asymptotic strain-gradient theory for one-dimensional continua
  
  • Thbaut Manon
  • Audoly Basile
  • Lestringant Claire
  Journal of the Mechanics and Physics of Solids, Elsevier, 2026, 206, pp.106392. (10.1016/j.jmps.2025.106392)
  DOI : 10.1016/j.jmps.2025.106392