"Unfortunately, the direct translation was not possible due to applying high electric fields in conductive physiological solutions such as blood as compared to tap water," Davalos said. However, the lessons learned and engineering that went into developing robust and reliable microsystems at SNL was instrumental in motivating his team to come up with a viable solution called contactless dielectrophoresis (cDEP).
Today, Davalos, an award-winning assistant professor of biomedical engineering at Virginia Tech, along with his graduate students and co-authors of the paper, Hadi Shafiee, John Caldwell, Erin A. Henslee, and Michael Sano, all of Blacksburg, have found a way to provide "the non-uniform electric field required for DEP that does not require electrodes to contact the sample fluid."
They named their variation cDEP since it does not require electrodes to contact the sample fluid; instead electrodes are capacitively coupled to a fluidic channel in his device through barriers that act as insulators. High-frequency electric fields are then applied to these electrodes, inducing an electric field in a channel in the device. Their initial studies illustrate the potential of this technique to identify cells through their unique electrical responses without fear of contamination from electrodes or significant joule heating.
The significance of this work is it "enables a robust method to screen for targeted cells based on the dielectrophoretic properties from an entire blood sample rather than a few microliters," Davalos, the director of Virginia Tech's Bioelectromechanical Systems Laboratory, explained.
|Contact: Lynn A. Nystrom|