Electrostatic droplet manipulation using electret as a voltage source

A novel low-voltage electrostatic droplet manipulation method, liquid dielectrophoresis on electret (L-DEPOE) is proposed. By using electret as a voltage source, a dielectric droplet can move between two electrodes by switching an external capacitor. A circuit model is developed to predict the electrostatic force acting on the droplet and the droplet motion. A prototype device has been microfabricated using glass substrates with ITO electrodes and CYTOP electret. Parylene protection layer on the top of CYTOP prevents charge decay of the electret. It is demonstrated that the silicone oil droplet is moved by switching the capacitor using a 5 V signal, which is much smaller than the voltage required for electrowetting on dielectrics (EWOD).