Modeling And Fabrication Of A Gravity Suported Microfluidic Electrowetting Pixel Based On An UV Stereolithography Polymer Substrate

We present a method to fabricate Electrowetting-on-Dielectric (EWOD) structures on rough UV-SLA (UV-Stereolithography) polymer surfaces, by planarizing the surface with a negative photoresist right before the electrode lift off process. The planarization and lift off procedure will enable us to insert EWOD electrodes inside chambers of different height, precisely the reservoir chamber and the visible pixel channel of a subsequently constructed microfluidic pixel cell. The fluid moves between the reservoir, hidden behind an intransparent small shutter platelet, and the visible fluid channel, switching the pixel on and off. In an upright orientation, the fluid flows back to the reservoir chamber supported by gravitational forces, after switching off the electrowetting actuation voltage.