In France, the building sector is the most energy consuming sector (43% of total energy), with 65% of this part directly linked to HVAC systems. The POCOMA project aims at reducing this energy consumption by shifting the problem of thermal comfort from the building scale to the level of the person through the design of heating or cooling textile.
We propose to design polymer membranes that modify the mid-IR properties of the textile to which they are attached, hence acting on the main heat transfer mechanism of the human body at rest. In this context, we will study two different structures, which can also be coupled: polymer membranes loaded with nano or even micro particles and membranes structured with photonic crystals at mid-IR wavelengths.
The consortium already has expertise in this field, so, rather than the proof of principle that has already been carried out previously, we are aiming to obtain demonstrators with a TRL5 compatible with the application (materials, size and process). The presence of the DAMART company, which is well known in the field, grants that the specific constraints linked to clothing application and industrial production will be considered at each stage of this project.
POCOMA is composed of four parts: modelling of the membranes, fabrication at laboratory scale and characterization of membranes properties, but also an industrialization aspect with research into textile functionalization and structuration processes compatible with the industrial scale.
Mid-IR optical and thermal behaviour of the membrane will be predicted by their simulation, as a function of their microstructure and/or charge loading. Models established in previous work will be used here but will be enhanced and pushed towards new possibilities, such as increasing the size of the nanoparticles beyond the micron, thus approaching the wavelength of interest, or taking into account the effect of humidity on the optical and thermal properties.
Dealing the manufacturing part, the main challenge is to use processes that can be industrialised afterwards. Thus "layer by layer" deposition process for charged membranes and "hot embossing" process for microstructured membranes will be mainly focused here. However, other solutions allowing the rapid production of samples will also be used. In addition, electrospinning will also be studied as a way of to combine the two strategies to produced microstructured-particles loaded-membranes.
The characterisation aspect will be organised on the one hand around the determination of the characteristics (optical complex index) of the materials in the mid-infrared, a little-explored field that is nevertheless necessary for the simulation of our structures. On the other hand, the membranes and membrane/textile complexes fabricated will also be qualified with regard to their optical and thermal properties and the results of these characterizations will be compared with simulation. In order to be able to qualitatively characterize small samples produced in the laboratory, the development of a thermal characterization set-up with enhanced performance (sensitivity) will be undertaken in the framework of this project.
Finally, the transition to sizes sample and structures compatible with standardised tests will be addressed. The functionalization of textiles by microstructured membranes will be carried out either by lamination on textiles of already structured membranes, or by polymer-coating on textile followed by plate to late or roll to roll hot embossing. This later is more compatible with the textile industry. DAMART will then qualify the product demonstrators in terms of thermal efficiency, comfort and resistance to use.
Madame MICHÈLE CARETTE (Institut d'Electronique, de Microélectronique et de Nanotechnologie)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Inst.FOTON Institut Fonctions Optiques pour les Technologies de l'informatiON
DAMART DSB / DIO R&D
IEMN Institut d'Electronique, de Microélectronique et de Nanotechnologie
GEMTEX GEnie des Matériaux TEXtiles
Help of the ANR 574,941 euros
Beginning and duration of the scientific project: February 2022 - 42 Months