Context: Position opened in the framework of the BioImp FEDER project funded by the European Union
Employer: University of Franche-Comté, FEMTO-ST Institute
Location: FEMTO-ST Institute, AS2M department, 24 rue Alain Savary, 25000 Besançon, France
Salary: gross salary around 2800 € per month
Duration: one year full-time employment, starting as soon as possible
Position open until filled. Candidates should provide a cover letter, a CV and a list of references via email to:
abdenbi.mohand@femto-st.fr
aude.bolopion@femto-st.fr

Context:
The interest for innovative devices performing cell analyses and sorting has been rapidly growing these last years. The FEMTO-ST Institute aims at proposing original solutions at the frontier between microfluidics and microrobotics. To control such devices, electric fields are of great interest since they can be used either for cell actuation or to determine the cell position. However, the combination of actuation/sensing capabilities
of electrodes is not usually discussed in the existing literature. In this context, FEMTO-ST institute aims at proposing advanced devices relying on electric fields for both sensing and actuation to control the cells within fluidic chip devices.
Objectives:
Several scientific works have demonstrated clearly the interest of electrical field to induce dielectrophoretic (DEP) forces that act on cells of interest in order to separate them from other cells and to sense their position inside the fluidic chips. Basically, the DEP force acts on neutral but polarized cell
placed on an inhomogeneous electric field produced by electrodes [1]. Moreover, it does not require any damaging chemical treatment, which makes it an effective means for cells sorting applications. In the other hand, electrical field can be used to sense the position of the cells. This technique is particularly useful when a high number of cells must be monitored at the same time because classical vision-based sensors are not relevant. With this technique, the position of the cells is obtained from the variation of
the impedance measured between two electrodes.
Despite this quit achievement in terms of actuating and sensing through electrical fields, there is still room for improvement. Coupling actuation and sensing capabilities would improve fluidic chips devices performances. In this context, FEMTO-ST institute aims at proposing advanced devices relying on
electric fields for both sensing and actuation to control the cells position within fluidic chip devices.
To reach this objective, the hired candidate will first focus on the design of actuating/sensing electrodes. Then, he/she will focus on the strategies that guarantee simultaneous measurement and actuation, and he/she will be in charge of the experimental validation of the proposed methodologies. This
work will benefit from the recent development of analytical models dedicated to compute the distribution of the electric field, and the dielectrophoretic force and torque made in FEMTO-ST and the implemented closed-loop control based on visual feedback [1,2], as well as works dedicated to position measurement based on the variation of the electric fields [3,4]. It will also benefit from the latest advancements from the development of electrodes with optimal topologies [5]. In addition to this challenging scientific aspect, the team of engineers working in the technological platforms of FEMTO-ST will support the hired candidate during the experimental validation of the developed electrodes and strategies.
[1] V. Gauthier, A. Bolopion, and M. Gauthier, "Analytical Formulation of the Electric Field Induced by Electrode Arrays: Towards Automated Dielectrophoretic Cell Sorting," Micromachines, vol. 8, p. 253, 2017.
[2] T. Michálek, A. Bolopion, Z. Hurák, and M. Gauthier “Control-oriented model of dielectrophoresis and electrorotation for arbitrarily shaped objects.” Phys. Rev. E : Physical Review E., vol 99, n°5, 10 pages, 2019.
[3] H. Daguerre, M. Solsona, J. Cottet, M. Gauthier, P. Renaud, A. Bolopion, “Positional Dependence of Particles and Cells in Microfluidic Electrical Impedance Flow Cytometry: Origin, Challenges and Opportunities.”. Lab on a chip, vol 20, n°20, pages 3665 – 3689, 2020.
[4] B. Brazey, J. Cottet, A. Bolopion, H. Van Lintel, P. Renaud, M. Gauthier, “Impedance based real-time position sensor for Lab- On-a-Chip devices.”. Lab on a chip, 18, pages 818 – 831, 2018.
[5] Abbas Homayouni-Amlashi, Laure Koebel, Alexis Lefevre, Abdenbi Mohand-Ousaid, Aude Bolopion, Topology optimization of the electrodes in dielectrophoresis-based devices, Computers & Structures, Volume 301, 2024,
107444, ISSN 0045-7949, https://doi.org/10.1016/j.compstruc.2024.107444.

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