Methods for depositing a measured amount of a species in a sealed cavity. In one example, a method for depositing molecules in a sealed cavity includes depositing a selected number of microcapsules in a cavity. Each of the microcapsules contains a predetermined amount of a first fluid. The cavity is sealed after the microcapsules are deposited. After the cavity is sealed the microcapsules are ruptured to release molecules of the first fluid into the cavity.