Figure 1. Schematic representation of ac-EHD induced nanoshearing.
The application of an ac field (e.g., alternating potential difference) across each electrode pair induces charges on the electrode surface. The lateral variation in number of induced charges and their spatial distribution gives rise to non-uniform local forces on the large and small electrode with the resultant force giving rise to lateral unidirectional flow towards the larger electrode. Since all the shear forces are contained within nanometers (λD = double layer thickness) of an electrode surface, these forces engender fluid flow to increase the number of target-antibody (blue) collisions whilst shearing away nonspecifically bound molecules (green and red).