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Reference : UMR8520-VINTHO-001
Workplace : VILLENEUVE D ASCQ
Date of publication : Wednesday, March 11, 2020
Type of Contract : FTC Scientist
Contract Period : 6 months
Expected date of employment : 1 May 2020
Proportion of work : Full time
Remuneration : between 2 643 and 3 047 euros before tax depending on previous work experience
Desired level of education : 5-year university degree
Experience required : Indifferent
The person recruited will join the BIOMEMS group of the IEMN in Villeneuve d'Ascq. His/her mission will consist in modelling, realizing and characterising a structured polymer membrane with specific optical properties in the mid-infrared range.
This work will be carried out within the framework of a contract between Damart (funding) and the CNRS (IEMN). It will start with a first period of 6 months. At the end, Damart will decide whether to finance an additional 6 months.
Over the last twenty years, intelligent textiles have developed rapidly, including through the integration of nanotechnologies, thus affecting many fields such as medical, construction, defence, civil security. We are interested in a new generation of textiles able to dynamically regulate temperature based on its physical nature and intrinsic structure [1,2]. Thermal comfort is related to the space between the skin and the textile, called microclimate. To control the temperature of the microclimate, we want to functionalize the textile indirectly by adding a structured and/or particle-filled flexible membrane.
In previous years, we have been interested in the patterning of photonic crystal polymer membranes, allowing the modulation of optical spectral responses in the emissivity range of the human body, the Mid-IR . We have studied the optical properties of different polymer membranes, studying their reflection, transmission and absorption responses in Mid-IR as a function of their physical nature and geometrical parameters. We then wrote the heat balance between the human body and the surrounding environment through the photonic membrane, taking into account the thermal mechanisms of conduction, convection and radiation. We showed that using a textured membrane, optical modulation in Mid-IR was accompanied by a variation in skin temperature with a differential of +1°C with respect to a non-textured membrane . Thus, when the room temperature is low, typically 20°C, the textured membrane acts as a heating element. So far, this thermoregulation property is based on theoretical considerations and demonstrations.
The successful candidate will rely on the IEMN's technology facilities for the realization of the membranes. Two types of structures will be considered: single polymer membranes that will be structured, or planar unstructured membranes that will be charged with near-micron-sized particles. These membranes will have to have a thickness between 10 and 100 µm in order to be manipulated and a surface compatible with the methods of characterisation (4cm2). Their surface will have to correspond to the surface necessary for the characterisation of the optical properties in the infra-red domain by FTIR (4 cm²). For these two structures, we will define the manufacturing processes leading to the realization of the membranes. The study will initially consist in defining the conditions for releasing the membranes from their supporting substrate. Then we will focus either on structuring them or on integrating particles homogeneously distributed in the material. The photonic membranes thus produced will be characterized by IR spectroscopy (FTIR). Finally, the experimental results obtained will be compared with numerical calculations.
In parallel to this experimental work, we will carry out a theoretical study on the different parameters influencing skin temperature.
We are looking for a candidate with skills in microtechnologies (photolithography, chemical attack, spin coating). The candidate will also have to master the physical concepts related to the propagation of electromagnetic waves in meta-materials as well as their simulation (codes based on FDTD, Comsol) and in terms of thermal transfer.
Degree required: PhD.
This work will be carried out at the IEMN (Institute of Electronics, Microelectronics and Nanotechnology) in Villeneuve d'Ascq.
The IEMN brings together in a single structure the regional research in a vast scientific field ranging from nanosciences to instrumentation.
Our specificity today is to bring together researchers with different cultures, approaches and motivations, and to build a continuity of knowledge from fundamental problems to applications. Today, nearly 500 people, including a hundred or so international researchers, work together.
The core of our activities is centred on micro and nanotechnologies and their applications in the fields of information, communication, transport and health. Our researchers have at their disposal exceptional experimental facilities, in particular technology and characterisation centres whose capabilities and performance are at the highest European level. The IEMN is part of the RENATECH network of major technology centres.
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