Micro and Nanomechanics for the Living group
Presentation
The activities of the Micro and Nanomechanics for the Living group belong in the field of human repair. This is a long-standing concern that is increasingly mobilizing researchers from various backgrounds.
The mechanical aspect is often underestimated. However, this is essential for the activity. It may concern the mechanical behaviour of bio-substitutes (implants and prostheses), or the mechanical behoviour of biological material. The understanding of remodelling mechanisms is essential for the development of new therapeutic techniques.
The group strives to:
- model and qualify the mechanical behaviour of hard or soft biological tissues
- study the impact of core and surface mechanical behaviour
- study the impact of the surface morphology of implantable or non-implantable medical devices on the expected function or on the occurrence of pathologies such as peri-implantitis.
The mechanics of biomaterials and biological materials are addressed via two main approaches:
- Experimental: it mainly uses tools for analyzing surface mechanical properties
- Numerical: it develops numerical materials in a phenomenological approach to best reach the response of the biological material to a stimulus
The tribological characteristics of dental implants and orthodontic arches are also considered.
This research is supported by ERDF-type European contracts, and in some cases requires collaboration with other groups in the laboratory or external partners:
- Nano-Bio-Materials for Life group
- Nanomaterials and Health group
- Surface and Interface, Chemical Reactivity of Materials group
- Virtual Hospital of Lorraine - School of Surgery
- CHAMPION Implants
Research topics
Experimental characterization of biomaterials and biological materials
Knowledge of the mechanical behaviour of biological materials is fundamental for a detailed understanding of their interaction with common inert materials. The results of these studies have both clinical and industrial applications (manufacture of implants).
Project:
ERDF ASCATIM project (2018- 2021)
Thesis:
Determination of mechanical characteristics of heart tissue : Jean-Philippe Jehl
Post-Doctoral fellows:
Membrane biocompatibilities Mélanie Lovera-Leroux ; Arnaud Voignier
Tribological behaviour and biocompatibility
The frictional force between orthodontic arches made of shape memory alloys and their brackets is an essential factor in orthodontics. Some of these arches are coated with rhodium which is thought to improve tribological characteristics. The sample sizes do not allow the use of classical methods to study tribological behaviour. Indeed, specific developments are required.
The development of biomimetic devices is a major issue nowadays. The optimization of their shapes and surface characteristics should make it possible to increase and adjust the properties of the implant/bone interface for better long-term osseointegration in dentistry. Specific points of this work concern:
- Research concerning new anatomical shapes (additive manufacturing)
- Design of new implant surfaces (zirconia deposition)
- Study of implant mechanics and tribology (both experimental and numerical aspects)
- Biological compatibility of anatomical implants made of new low modulus titanium alloy (co-culture test of fibroblast and macrophage cells on various surfaces)
Project:
ERDF IMPLANTS Project (2018- 2021)
Post-Doctoral fellow:
Tribological behaviour of Implants, biocompatibility of implant surfaces (Gaël Pierson)
Article:
Interaction implant-bone as a micropolar elastic medium: porosity impact of the hard living media, Gaël Pierson, Richard Kouitat Njiwa, Pierre Bravetti, International Journal of Theoretical and Applied Multiscale Mechanics, 2020 Vol.3 No.3, pp.229 – 244
Modelling the mechanical behaviour of biological materials
A long-standing concern of scientists has been the mathematical formulation of laws governing natural processes. The solutions of these mathematical models make it possible to explore the established model, to make predictions or to envisage various future scenarios. In other words carrying out quantitative and predictive experiments has become possible.
The complexity of the mathematical model often requires the assistance of numerical simulations. With respect to biological materials, the objectives of behaviour modelling are numerous and deal with diagnosis, therapy, bio-substitutes or surgery. In addition to being the site for complex exchange phenomena and evolutionary mechanisms, living materials are heterogeneous, multi-scale (often nested) and respond to stimuli on different time scales. These characteristics show the difficulties that must be overcome to model living environments in detail. The group has opted for an extended continuous medium approach. This allows the translation at the macroscopic scale of some relevant informations from lower scales, through tensorial scale coupling magnitudes.
Articles:
- Coupling BEM and the Local Point Interpolation for the Solution of Anisotropic Elastic Nonlinear, Multi-Physics and Multi-fields Problems. R. Kouitat Njiwa, G. Pierson, A. Voignier, International journal of Computational Methods (2019)
- Modeling Heart Tissue as a micromorphic medium: a numerical investigation, N. Thurieau, J-Ph. Jehl, R. Kouitat Njiwa, N. Tran, P. Maureira, Journal of Mechanics in Medecine and Biology vol 17(5) (2017)
Know-how
- Mathematical modelling and numerical simulation
- Nano-indentation
- Nano-tribology
- Implantations
- Dentistry – Orthodontics
Members
Professors, assistant professors
- Pierre BRAVETTI
- Richard KOUITAT
PhD students
- Mathieu BRAVETTI
- Alex Perez TCHINDA
Publications
Contact
Head of the group
Richard KOUITAT NJIWA
richard.kouitat@univ-lorraine.fr
+33 (0) 3 72 74 25 16
Nancy-Artem
Institut Jean Lamour
Campus Artem
2 allée André Guinier - BP 50840
54011 NANCY Cedex