Dosing and sealing of fluid-based electro-optical devices and displays

A method for manufacturing an electrofluidic device comprising the steps of providing a first plate with features for holding a first fluid, filling a first fluid into features on a first plate; providing a second plate and sealing a second plate onto the first plate forming stacked plates with at least one cavity between the plates, and leaving at least one fill port for a second fluid. Thereafter, the stacked plates are cooled to increase the viscosity of the first fluid so that the first fluid maintains a fixed position as a second fluid is filled into the cavity. Methods are disclosed.