par Dongo, Patrice Desire
Président du jury Haut, Benoît
Promoteur Hendrick, Patrick
Publication Non publié, 2024-12-11
Thèse de doctorat
Résumé : The early detection of ice formation on surfaces is of critical importance for the safety of numerous applications, particularly in sectors such as aviation, telecommunications, and renewable energy. The accumulation of ice can have a significant detrimental impact on the performance and safety of a range of systems, including those used in aviation, such as aircraft wings, and in the energy sector, such as wind turbines. Conventional ice detection techniques frequently necessitate the use of sophisticated and costly instrumentation, which constrains their potential for broader implementation.To contribute to give a response to this challenge this thesis introduces two innovative approaches of ice detection systems which one exploit the thermal properties of ice and the other the intrinsic properties of a conductive. The first system employs a heat-pulse technique, whereby a controlled heat pulse is applied to the surface and the subsequent temperature evolution is monitored. By analysing the relaxation time of the temperature profile, the presence of ice can be accurately inferred. The system's core comprises a sensor fabricated using graphene films embedded in pre-preg layers, which are commonly used in aeronautical applications. In conjunction with thermocouples, this sensor network enables the precise measurement of temperature profiles at various locations on the surface. The detection of ice is based on the principle that ice has a higher thermal capacity than air, which allows for the identification of icy spots.The second system investigates the potential of resistive sensors based on conductive polymer for ice detection. Despite their potential advantages, resistive sensors, and hygroscopic ionic-electronic conductors in particular, have been underexplored in the context of ice detection. This thesis introduces mixed ionic-electronic polymer conductors (MIEC), specifically poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), as a promising material for resistive ice sensing. The PEDOT:PSS-based sensor exhibits a pronounced increase in electrical resistance during the phase transition from liquid water to ice. This change is attributed to the impact of ice crystal formation on the morphology and electronic transport within the polymer. The successful integration of the sensing layer into pre-preg layers for aeronautical applications validates the feasibility of this ice detection approach. This thesis presents findings based on numerical simulations, experimental investigations, and practical demonstrations, which collectively establish the efficacy of both heat-pulse and resistive sensing techniques for ice detection.

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