Dielectric Characterisation of Single Microalgae Cell Using Electrorotation Measurements

This study demonstrates the electrorotation of single microalgae cells captured in the center of a set of planar microelectrodes within a microfluidic device, and compares the rotational speeds of single microalgae cells obtained in experiments and theoretical calculations. Negative dielectrophoresis force and rotational electric field are generated by the microelectrode set to position and rotate single microalgae cells. The rotational speed of single microalgae cells in the microfluidic device is calculated automatically using an image-processing algorithm. The electrorotation spectra of microalgae cells enduring different periods of nitrogen starvation agree with the simulation results for lowand high-lipid content cells. These results show the great potential of using electrorotation in quantifying the dielectric characteristics of microalgae cells.