Kevin Keim | EPFL Graph Search

Professional Experience since 09/2016 Doctoral Assistant, École Polytechnique Fédérale de Lausanne, Switzerland; 11/2014 – 11/2015 Master Thesis, Technical University of Munich, Germany, Department of Electrical and Computer Engineering, Chair for Molecular Electronics 06/2013 – 09/2013 Bachelor Thesis, École Polytechnique fédérale de Lausanne, Switzerland Laboratoire des Materiaux Semiconductors 10/2011 Internship, Daimler AG, Mannheim, Competence center for emission-free Mobility • Analyzed a CAD engine model and developed guide lines for its assembly 07/2009 – 03/2010 Military service in ski unit, Gebirgsfernmeldebataillon 210, Bad Reichenhall Academic education since 09/2016 Ph.D. program in Microsystems and Microelectronics École Polytechnique Fédérale de Lausanne, Switzerland Laboratory of Life Sciences Electronics 10/2013 – 06/2016 M.Sc. Physics, Technical University of Munich, Germany • Specialization: Condensed Matter Physics 2016 Semester abroad, Nanyang Technological University, Singapore • Courses: Advanced Semiconductor Physics, Advanced Wafer Processing, Data Structures, Chinese Language 1 10/2010 – 09/2013 B.Sc. Physics, Technical University of Munich, Germany • Specialization: Condensed Matter Physics 2012 Semester abroad, École Polytechnique, Paris, France • Courses: Quantum and Statistical Physics, Fluids Mechanics, Experimental Project in Physics, French B1 08/2000 – 06/2009 Abitur, Altes Kurfürstliches Gymnasium, Bensheim, Germany 08/2006 – 06/2007 Diploma, Fountain Lake High School, Hot Springs, AR, USA

Particle-sorting fluidic device and methods for using thereof

Carlotta Guiducci, Kevin Keim, Gloria Porro

Device, system and method for sorting particles comprised into a fluid are disclosed that improve the current settings of deterministic lateral displacement (DLD)-based microfluidic devices, so to sort and detect small particles such as extracellular vesicles, while exploiting all the advantages and throughput of well-known DLD and dielectrophoresis techniques. The device is characterized by the presence of a plurality of three-dimensional electrodes having a longitudinal section with a narrower first end and a wider, opposed second end.

2022

In-flow measurement of cell-cell adhesion using oscillatory inertial microfluidics

Kevin Keim

Multicellular clusters in circulation can exhibit a substantially different function and biomarker significance compared to individual cells. Notably, clusters of circulating tumor cells (CTCs) are much more effective initiators of metastasis than single CTCs, and correlate with worse patient prognoses. Measuring the cell-cell adhesion strength of CTC clusters is a critical step towards understanding their subsistence in the circulation and mechanism of elevated tumorigenicity. However, measuring cell-cell adhesion forces in flow is elusive using existing methods. Here, we report an oscillatory inertial microfluidics system which exerts a repeating fluidic force profile on suspended cell doublets to determine their cell-cell adhesion strength (F-s), without any biophysical modifications to the cell surface and physiological morphology. Using our system, we analyzed a large number (N > 500) of doublets from a patient-derived breast cancer CTC line. We discovered that the cell-cell adhesion strength of CTC doublets varied almost 20-fold between the weakly adhered (F-s < 28 nN) and strongly bound subpopulations (F-s > 542 nN). Our system can be used with other cancer or noncancer cells without restrictions, and may be used for rapid screening of drugs aiming to disrupt the highly-metastatic CTC clusters in circulation.

ROYAL SOC CHEMISTRY2020

Selective Retrieval of Individual Cells from Microfluidic Arrays Combining Dielectrophoretic Force and Directed Hydrodynamic Flow

Bart Deplancke, Gabriele Gambardella, Carlotta Guiducci, Kevin Keim, Jörn Pezoldt, Pierre-Emmanuel Marie Thiriet

Hydrodynamic-based microfluidic platforms enable single-cell arraying and analysis over time. Despite the advantages of established microfluidic systems, long-term analysis and proliferation of cells selected in such devices require off-chip recovery of cells as well as an investigation of on-chip analysis on cell phenotype, requirements still largely unmet. Here, we introduce a device for single-cell isolation, selective retrieval and off-chip recovery. To this end, singularly addressable three-dimensional electrodes are embedded within a microfluidic channel, allowing the selective release of single cells from their trapping site through application of a negative dielectrophoretic (DEP) force. Selective capture and release are carried out in standard culture medium and cells can be subsequently mitigated towards a recovery well using micro-engineered hybrid SU-8/PDMS pneumatic valves. Importantly, transcriptional analysis of recovered cells revealed only marginal alteration of their molecular profile upon DEP application, underscored by minor transcriptional changes induced upon injection into the microfluidic device. Therefore, the established microfluidic system combining targeted DEP manipulation with downstream hydrodynamic coordination of single cells provides a powerful means to handle and manipulate individual cells within one device.

MDPI2020