Electricity for Fluidics and Bio-Devices

This chapter is focused on biomaterial interaction with electromagnetic fields. It gives a wide and deep introduction of biological medium and their electromagnetic properties, which can be used to sense and analyze tissue or cells within lab-on-chip. It consists of three complementary parts. A recall of electrokinetics laws is done and is applied to biological medium (electrolyte with fluid motion) in the first section. The scaling factor towards nano-scale is highlighted considering the ionic concentration distribution. The second section deals with dielectrophoresis forces (DEP), which results from the cell polarization under non-uniform electric field. The dielectric modeling of cells and their DEP response are depicted. Taking benefits of cell dielectric behavior, the applications such as cell sorting, trapping and characterization with electrorotation are presented. The last section introduces the biomaterial behavior at radiofrequency range (from MHz up to several tens of GHz). Applications using thee relaxation times occurring at such high frequency are described to sense or characterize biological medium. Electric Impedance Spectroscopy and Radio-Frequency devices are thus introduced.