(606c) Bioparticle Manipulation with Insulator-Based Dielectrophoresis

Dielectrophoresis (DEP) is the motion of particles in due to polarization effects in nonuniform electric fields; this electrokinetic transport mechanism has a great potential for the manipulation of a wide array of bioparticles, ranging from biomolecules to microorganisms. Traditionally, DEP has been carried out employing arrays of microelectrodes, however, employing microelectrodes has some drawbacks such as high cost and loss of functionality due to fouling. Insulator-based dielectrophoresis (iDEP) is an attractive alternative, since it employs arrays of insulating structures, instead of electrodes, to create nonuniform electric fields; resulting in inexpensive and robust devices. This study presents the application of iDEP for the manipulation and concentration of different types of bioparticles (from proteins to microalgae). Glass and polymeric microdevices containing channels with cylindrical insulating posts were employed to trap and concentrate bioparticles. A sample of bioparticles was introduced into the microchannel, then; a direct current (DC) electric field was applied across the post array, creating regions of higher and lower electric field intensity, i.e. dielectrophoretic traps. Electroosmotic flow was generated to pump the suspending liquid through the microchannel, while the bioparticles were immobilized and concentrated at the dielectrophoretic traps between the cylindrical posts. The dielectrophoretic response of the bioparticles was recorded in the form of videos and pictures. Experiments were conducted varying the electric field, pH and conductivity of the suspending medium, in order to study the effect of these parameters on the dielectrophoretic response of the bioparticles. Successful trapping of the different types of bioparticles was achieved, demonstrating the great potential of iDEP as a technique for bioparticle manipulation.