Electromanipulation and separation of cells using travelling electric fields

A multi-layer micro-electrode structure has been developed for the selective manipulation and separation of bioparticles using travelling field dielectrophoresis effects. An important feature is that, in the separation process, the selected particles move in a stationary supporting fluid. Stationary suspensions of viable and non-viable yeast cells were used as a model system to demonstrate the general application of this device for the selective retention or transport of bioparticles in suspended mixtures. The efficiency of this process depends on the dielectric properties of the particles and their suspending medium, and is a sensitive function of the frequency of the travelling field. Apart from their use as particle separators, such micro-electrode devices are also envisaged to form integral components in the development of `biofactory on a chip' technology.