PARTICLE MICROMANIPULATOR CONSISTING OF 2 ORTHOGONAL CHANNELS WITH TRAVELING-WAVE ELECTRODE STRUCTURES

In the paper experimental and numerical results for a simple particle micromanipulator fabricated in silicon technology are presented. It co nsists of three orthogonal liquid filled channels above meander-shaped planar electrode strips. By applying appropriate alternating, rotatin g or travelling electric fields in the chamber dielectric forces actin g on particles suspended in the liquid are induced allowing trapping, movement and separation of them. The efficient manipulation of small p articles with typical dimensions of several micrometers using electro- gradient techniques (EGT) requires electrode structures of the same si ze. Due to the complex electrode geometry a numerical procedure is use d for calculation of particle trajectories and optimising the design. In the micro range small fabrication defects are likely to cause large changes of the properties of the manipulator. Therefore, a test proce dure based on electrode processes in aqueous media and the pH-dependen t fluorescence intensity of a marker solution which enabled us to visu alise the working states, surface coatings and fabrication defects of microstructured electrodes via a microscope is introduced.