Controllable cell manipulation in a microfluidic pipette-tip design using capacitive coupling of electric fields

• Published in: Lab on a chip Vol. 19; no. 23; pp. 3997 - 46
• Main Authors: Wimberger, Terje, Peham, Johannes R, Ehmoser, Eva-Kathrin, Wassermann, Klemens J
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 07.12.2019
• Subjects: Biological effects; Biological properties; Coated electrodes; Coupling; Dependence; Electric fields; Electrical resistivity; Electrolytic cells; Electroporation; Energy dissipation; Field strength; Gold coatings; Microfluidics
• ISSN: 1473-0197; 1473-0189
• DOI: 10.1039/c9lc00927b

Systems designed toward cell manipulation by electric fields are inherently challenged by energy dissipation along the electrode-electrolyte interface. A promising remedy is the introduction of high- k electrode passivation, enabling efficient capacitive coupling of electric fields into biological samples. We present the implementation of this strategy in a reusable pipette tip design featuring a 10 μl chamber volume for life science applications. Prototype validation and comparison to conductive gold-coated electrodes reveal a consistent and controllable biological effect that significantly increases the reproducibility of lysis events. The system provides precise descriptions of HEK-293 lysis dependency to variables such as field strength, frequency, and conductivity. Over 80% of cells were reversibly electroporated with minimal electrical lysis over a broad range of field settings. Successful transfection requires exponential decay pulses and showcases how modulating capacitive coupling can advance our understanding of fundamental mechanics in the field of electroporation. Capacitive coupling of electric fields diminishes energy dissipation and offers superior control over field parameters, resulting in predictable biological outcomes.