ED Sciences Physiques et de l'Ingénieur
Electromagnetic energy harvesting 'meta-skin' applied for WBAN applications
by Elie ZARAKET (Laboratoire de l'Intégration du Matériau au Système)
The defense will take place at 10h00 - Amphithéâtre Jean-Paul DOM Amphithéâtre Jean-Paul DOM, laboratoire IMS (Bâtiment A31) 351 Cours de la Libération, 33405 Talence Cedex, France
in front of the jury composed of
- Valérie VIGNERAS LEFEBVRE - Professeur - Bordeaux INP - Directeur de these
- Bruno ALLARD - Professeur - INSA Lyon - Rapporteur
- Xavier BEGAUD - Professeur - LTCI, Telecom Paris, Institut Polytechnique de Paris - Rapporteur
- Michel AILLERIE - Professeur - LMOPS, Université de Lorraine - Examinateur
Recent advancements in remote healthcare and biomedical technologies are rapidly accelerating the development of flexible, wearable devices for continuous health monitoring. The Internet of Medical Things (IoMT) market is projected to grow at a Compound Annual Growth Rate (CAGR) of 38.5% between 2024 and 2032, with Wireless Body Area Networks (WBAN) serving as a critical driver of this growth. Thus far, the expansion of IoT devices has faced challenges in designing wearable, miniaturized, and biocompatible prototypes with power-autonomous operation for physiological sensors. Therefore, this thesis aims to develop a wearable Energy-Harvesting (EH) system, in the form of a skin-applied device, designed for monitoring physiological conditions. The primary challenge of this research is the impact of the human body on the antenna system's performance when positioned directly on the skin. The body absorbs part of the radiation, which significantly reduces the efficiency of the EH system. In this context, Artificial Magnetic Conductors (AMC)s present a promising solution as reflectors for low-profile antennas, in the GSM and WiFi bands. By leveraging their inherent zero-phase reflection properties, AMCs improve antenna performance while eliminating the need for a bulky quarter-wave backplane. The real-world tests of the dual-band AMC-backed antenna showed minimal performance distortion for WBAN applications. Finally, the integration of a designed RF-to-DC converter enables the rectenna to function as an autonomous wearable energy harvester, providing a rectified voltage of 1V at approximately -17.5 dBm, suitable for powering certain physiological sensors.