Quantitative analysis of the three‐dimensional trap stiffness of a dielectrophoretic corral trap

• Published in: Electrophoresis Vol. 42; no. 5; pp. 644 - 655
• Main Authors: Rahman, Mohammad Rizwen Ur, Kwak, Tae Joon, Woehl, Jörg C., Chang, Woo‐Jin
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.03.2021
• Subjects: Corral trap; Dielectrophoresis; Electric fields; Finite element method; Image analysis; Microfluidic device; Microfluidic devices; Microparticle trap; Polystyrene resins; Quantitative analysis; Stiffness; Three‐dimensional trap stiffness; Trapped particles; Trapping; Three-dimensional trap stiffness; Microparticle trap; Dielectrophoresis; Corral trap; Microfluidic device
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.202000222

Dielectrophoresis is a robust approach for the manipulation and separation of (bio)particles using microfluidic platforms. We developed a dielectrophoretic corral trap in a microfluidic device that utilizes negative dielectrophoresis to capture single spherical polystyrene particles. Circular‐shaped micron‐size traps were employed inside the device and the three‐dimensional trap stiffness (restoring trapping force from equilibrium trapping location) was analyzed using 4.42 μm particles and 1 MHz of an alternating electric field from 6 VP‐P to 10 VP‐P. The trap stiffness increased exponentially in the x‐ and y‐direction, and linearly in the z‐direction. Image analysis of the trapped particle movements revealed that the trap stiffness is increased 608.4, 539.3, and 79.7% by increasing the voltage from 6 VP‐P to 10 VP‐P in the x‐, y‐, and z‐direction, respectively. The trap stiffness calculated from a finite element simulation of the device confirmed the experimental results. This analysis provides important insights to predict the trapping location, strength of the trapping, and optimum geometry for single particle trapping and its applications such as single‐molecule analysis and drug discovery.