Removal of Fixing Point

The second constraint that we tried was removal of the fixing point. It was unconsciously done already at preliminary trial. But, now we can remove the electrodes on the bottom from the assumption. If the gel is placed below the multiple electrodes in a plane, the gravity force will keep the distance between the electrodes and the gel. Therefore, the fixing point should be removed. 

5 Spatially-Varying Electric Field Design by Planer Electrodes 

If the electrode above the center of the gel is anode, cationic surfactant molecules adsorb on the reverse side of the anionic gel facing the electrodes, which cause the gel to deform into concave shape. This is because the anode electrode above the center of the gel repels the surfactant molecules. 

---