Benoit BRAZEY : "Estimation by impedance measuremnt techniques"

PhD  work :   Position estimation by impedance measurement techniques: applications to microfluidic chips

Abstract : This thesis is part of the general application framework of single cell analysis. In order to improve the selectivity of single cell sorting, FEMTO-ST teams propose to control in closed loop the trajectories of the cells in real ti me du ring their journey in the chips dedicated to sorting. In this context, my thesis work focuses on an innovative method for real-time detection of cell position, directly integrated into chips and based on the physical principle of impedance measurement. When a cell passes through a microchannel, it changes the measurable impedance between electrodes placed on the edges of the channel. A generic method for formulating impedance variations as a function of particle position has been proposed (direct mode!). A method for estimating the position of a particle based on impedance measurements has also been proposed (inverse mode!). It uses an extended Kalman filter, allowing data from several pairs of electrodes to be merged, and exploiting available information such as measurement noise distribution and particle dynamic model. The validation of the method was carried out on an experimental bench that was developed du ring this thesis and on numerical simulations. This work shows the relevance of using impedance measurement to build a position sensor for particles immersed in amicrochannel. This method is an alternative to the use of optical microscopes and has the advantage of being very compact.

Evaluation Commitee :
- Mr Michaël GAUTHIER, CNRS reseach director – University of Bourgogne – Franche-Comté, PhD Supervisor
- Mrs Aude BOLOPION, CNRS researcher, University of Bourgogne – Franche-Comté, PhD Co-Supervisor
- Mr Antoine FERREIRA, Full Professor INSA Centre Val de Loire, Reporter
- Mrs Christine PRELLE, Full Professor Université Technologique de Compiègne, Reporter
- Mr Franck CHOLLET,  Full Professor University of Bourgogne - Franche-Comté, Reviewer
- Mr Eric BIDEAUX, Full Professor INSA de Lyon, Reviewer

Location : ENSMM, 26 chemin de l'Epitaphe, 25000 BESANCON, Amphithéâtre Jules Haag