Dielectrophoresis

In dielectrophoresis an inhomogeneous electric field - in direct current ( DC) and alternating current ( AC) - used for the manipulation of particles / particles. Due to the inhomogeneous field a dipole moment is induced in the particles, which then enters into interaction with the applied field: the particles experience a force and move - depending on the field and dipole moment - in areas of high (positive DEP) or lower (negative DEP) field strength. The force is proportional to the volume of the particles. Thus can be trapped particle as a function of their size in a " field cage ". Using dielectrophoresis is in sorting and detection of nanoparticles, viruses, etc.

A cylinder which is parallel to the field and having a radius half length of dielectric constant in a medium with constant, the dielectrophoretic force is given by:

An application in biology, for example, to move a cell, regardless of their surface charge in an inhomogeneous alternating electric field. For a polarizable ball (for example, a spherical cell) in good approximation the following equation applies:

• Electrophoresis