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Study of a secured wireless piezoelectric power transmitter for medical implants


Keywords: piezoelectricity, continuum mechanics, chaos, wireless power transfer, mechatronics, cryptography

Abstract: Energy Harvesting and Wireless Power Transfer are two quickly spreading technics to increase wireless devices autonomy. The medical field also need to evolve, especially in the medical implants sector where surgery is still needed to replace batteries. This operation may be risky for the patient and it would be interesting to think about a wireless implant charger device.
The objective of this thesis is to conceive a wireless piezoelectric device for medical implants. The main constraints about the power transfer is linked to the physiological restrictions of the human body. This thesis will focus on the ultrasonic waves, offering an alternative to induction and which is already chosen for medical imaging and for therapeutic purposes. The efficiency of the conversion will be maximised to avoid putting too much constraint on the biological tissues. Finally, the wireless transfer need to be secured to avoid any hacking of the system, which is why a study on cryptography by chaotic synchronisation will be carried out.
The thesis will be divided in three parts. First, the modelling of the power transfer function by ultrasound in order to optimise the electric part located in the implant. Second, the design of a proof of concept and the electromechanical characterization of the device. Third, securing of the transfer by chaotic cryptography.


Thesis director: Skandar BASROUR (TIMA - CDSI)
Thesis supervisor: Martial DEFOORT (TIMA - CDSI)
Thesis started on: Nov. 2021
Doctoral school: EEATS

Submitted on January 12, 2022

Updated on December 12, 2023