We present experiments on dielectrophoretic (DEP) separation and trapping performed in a titanium-based micro channel linear electrode array.
The micro channel was fabricated in collaboration with Y. Zhang from N. MacDonald's group. The device consists of an array of 24 electrodes sitting on the bottom of 200 microns wide, 30 microns deep and 6 millimeters long titanium channel. The electrodes are 20 microns wide with a pitch of 40 microns. The channel is versatile and biocompatible. The device is designed to allow multi-frequency DEP (p-DEP and n-DEP) in contrast with most of the previous, single-frequency designs.
We experimentally demonstrated the ability to separate fluorescent polystyrene particles based or their size. More experiments are in process to study the separation for:
- biological samples
- different electrolyte conductivities
The device also allows the use of traveling waves to move particles using non-homogeneities in electric-field phase-driven DEP. The idea is to separate the particle and move them in specific location. The first experiments are in process. By tuning the multi-frequency signal, we have also shown the ability of producing strong micro mixing. Once the particles are trapped, we have shown experimentally and theoretically that a small perturbation can strongly destabilized the flow.