The goal of this project is to investigate high frequency (10-160 MHz) dielectrophoresis (DEP) as a tool for sorting cells based on differences in cytoplasmic conductivity and other interior features. The PI will focus on microalgae due to the ease of controlling and measuring cytoplasmic lipid content. The primary hypothesis is that increases in lipid content within the microalgal cell will change the high frequency DEP response due to a decrease in cytoplasmic conductivity. In particular, it is expected that the upper crossover frequency (i.e., the frequency at which no DEP-induced motion is observed) will be shifted to lower frequencies as the volume of lipids within the cell increases. A range of frequencies should exist where cells with high lipid content and low lipid content can be separated since the DEP-induced motions will be in opposite directions. To test this hypothesis, extensive analytical, numerical, and experimental studies of high frequency DEP are proposed to determine the correlation between the lipid content of a microalgal cell and the cell?s high frequency DEP response. The lipid content will be quantified via fluorescent microscopy. A high throughput screening device that can sort microalgae on the basis of lipid content will be designed and built for the purpose of exploring one potential application of this technology. Lastly, a comprehensive study will be performed to discover what other cells can be separated using high frequency DEP. This approach is potentially transformative, as it is label-free and depends on intrinsic cell properties. In particular, high frequency DEP could have much broader applications when compared to low frequency DEP as it probes the interior of the cell as opposed the cell membrane. Broader Impacts. Microalgae technology has the potential to supply the US with significant quantities of biofuels suitable for transportation. High-frequency DEP may have other applications beyond microalgae such as drug discovery and cancer research. The results of this project will be presented at conferences and in journals to both the DEP and microalgae communities in order to disseminate the results as widely as possible. Underrepresented graduate and undergraduates students have already been identified for this work. The interdisciplinary nature of this project will provide excellent training opportunities for the students giving them exposure to both microtechnology and microbiology. These activities will support continued development of an interdisciplinary class, "Introduction to Microtechnology," at the University of Nevada, Reno.
