Journal
ELECTROPHORESIS
Volume 36, Issue 13, Pages 1386-1395Publisher
WILEY
DOI: 10.1002/elps.201400454
Keywords
Fluidic dielectrophoresis; Interfacial polarization; Liquid interface; Micro channel
Funding
- NSF CAREER Award [CBET-1351253]
- Div Of Chem, Bioeng, Env, & Transp Sys
- Directorate For Engineering [1351253] Funding Source: National Science Foundation
Ask authors/readers for more resources
Traditional particle-based dielectrophoresis has been exploited to manipulate bubbles, particles, biomolecules, and cells. In this work, we investigate analytically and experimentally how to utilize Maxwell-Wagner polarization to initiate fluidic dielectrophoresis (fDEP) at electrically polarizable aqueous liquid-liquid interfaces. In fDEP, an AC electric field is applied across a liquid electrical interface created between two coflowing fluid streams with different electrical properties. When potentials as low as 2 volts are applied, we observe a frequency-dependent interfacial displacement that is dependent on the relative differences in the electrical conductivity (Delta sigma) and dielectric constant (Delta epsilon) between the two liquids. At low frequency this deflection is independent of dielectric constant, while at high frequency it is independent of electrical conductivity. At intermediate frequencies, we observe an fDEP cross-over frequency that is independent of applied voltage, sensitive to both fluid electrical properties, and where no displacement is observed. An analytical fDEP polarization model is presented that accurately predicts the liquid interfacial cross-over frequency, the dependence of interfacial displacement on liquid electrical conductivity and dielectric constant, and accurately scales the measured fDEP displacement data. The results show that miscible aqueous liquid interfaces are capable of polarizing under AC electric fields, and being precisely deflected in a direction and magnitude that is dependent on the applied electric field frequency.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available