Special Heat Transfer Mechanisms: Active and Passive Thermal Diodes - Magnetocaloric Energy Conversion: From Theory to Applications - page 236

Fig. 6.20 The dielectrophoretic ow of a neutral particle, a no net force is established over the

particle due to the uniform electric eld, b negative dielectrophoresis, c positive dielectrophoresis

fl

Fig. 6.21 An example of electroosmotic fl ow

6.4.1.3 Electroosmosis

Electroosmotic fl ow (Fig. 6.21 ) relates to a bulk ionized fl uid motion under the

in eld that is parallel to the surfaces in the

presence of an established double layer (EDL), which represents a thin region of net
charge density near the two-phase interface.
The EDL layer is formed by a static Stern layer and a Gouy-Chapman layer,
respectively, and is developed between the electrolyte liquid and the charged sur-
face. Negative ions from the liquid are attracted to the surface. A thin static charge
layer is formed (Stern layer) on the surface due to the electrostatic force. The
second, thicker and mobile (can be moved by an electric

fl uence of an externally applied electric

eld) layer is called the
Gouy-Chapman layer. The thickness of the EDL region can vary from 10 nm to a
few 100 nm [ 90 ]. The EDL layer is moved by the electric

eld as a result of the