Electro-Hydro-Dynamic (EHD) Micropumps with Electrode Protection by Parylene and Gelatin

This paper describes an ejection-type electro-hydro-dynamic (EHD) micropump using various types of polymers to protect the electrodes. The polymer layers of parylene and crosslinked gelatin were shown to protect the gold electrodes from electrolytic aging. The pump chip is packaged by the polydimethylsiloxane (PDMS) bonding technique. The results show that the polymer protection layers are successful in prolonging the operation lifetime. They can also provide the inner walls of channels with different surface properties for the working liquid to be driven through