Helena Teixido, Jeroen Staal, Baris Caglar, Véronique Michaud
A visual description of flow characteristics defined by several phenomena acting simultaneously
The Dynaflow project aims to probe the dynamics of flow in fibrous porous media, as used in advanced composite materials, by addressing several main points. i) One aim is to further develop the in-situ experimental methods to analyze multiphase flow processing, using advanced and novel techniques available at CSEM to enable the macro-scale observation of dynamic resin flow patterns. ii) Results of macro-scale observations will be coupled with local observation of frozen microstructures using microtomography. iii) The multiscale in-situ experimental data will feed process models that account for multiphase fluid flow effects, extended to velocity-dependent capillary forces and hierarchical pore structures.
Funding source: Swiss National Science Foundation http://p3.snf.ch/project-182669
Project partner: CSEM – Centre Suisse d’Electronique et de Microtechnique SA
Publication: Caglar B, Tekin C, Karasu F, Michaud V. Assessment of capillary phenomena in liquid composite molding, Composites Part A: Applied Science and Manufacturing, 120, 73-83, 2019. https://doi.org/10.1016/j.compositesa.2019.02.018
Arif Poothanari, Yves Leterrier, Véronique Michaud
Morphology of the aminated microfibrillated cellulose
Hybrid piezoelectric nanocomposites based on surface modified graphene/microfibrillated cellulose (MFC) and poly(vinylidene fluoride) (PVDF) are developed for energy harvesting applications. The role of the fillers is first to promote the crystallization of PVDF into its polar beta-phase, and second to achieve exceptional thermomechanical stability. Fluorinated and amine-induced H-bonded interfaces are produced for both graphene and MFC and their influence on the crystalline state, mechanical and electrical properties of composites is systematically explored within a broad compositional space. Pristine and fluorinated fillers hinder beta-phase, in contrast to aminated fillers, which lead to the best property combination.
Funding source: Swiss Government Excellence Scholarships
Collaborations with Prof. Damjanovic, EPFL
Kyungjin Kim, Julien Carron, Yves Leterrier
Parylene based multilayer barriers coated on flexible interdigitated electrodes
XInoCaps is a Comelec SA-LSBI-LPAC collaboration to develop organic/inorganic barrier coatings for implantable medical devices. The multilayer coatings combine Parylene C and inorganic ALD/PECVD films. These coatings are produced in a new kind of hybrid equipment developed by Comelec, allowing alternative depositions in a single deposition chamber. Specifically, LPAC designs and characterizes the multilayer structure to improve both flexibility and barrier performance in terms of crack onset strain, oxygen/water vapor permeability, and lifetime of barrier coated electrodes. Our ultimate goal is to standardize such design and procedure to coat any fabricated flexible devices at low temperature and demonstrate a new generation of soft biomedical implants with improved lifetime reliability.
Funding source: Innosuisse
· Comelec SA (http://www.comelec.ch)
· Laboratory for Soft Bioelectronic Interfaces (LSBI-EPFL)