We recently reported ionomigration of pores and argon bubbles in the direction of O2- flow in nearly dense 8YSZ; ionomigration also enables electrosintering without grain growth in porous 8YSZ, yielding full-density ceramics that are initially 70% dense. (Advanced Energy Materials, in press, 2012). These experiments were conducted at below 850oC without Joule heating, at a voltage below the electrolytic limit (~2 V). Since pores and gas bubbles are electrically neutral, and ion flows carry no momentum, ionomigration cannot be related to force/momentum-driven electromigration seen in charged colloids and metal interconnects. Here I will describe in detail the essential aspects which enable the experiments and their understanding: (a) in-situ thermometry using impedance spectroscopy, (b) coupling between O2- lattice diffusion and Zr4+/Y3+ surface/interface diffusion, (c) size dependence and second-phase coalescence in ionomigration, and (d) implications to SOFC and SOEC. Additional experiments on other inclusions and at lower temperatures will also be discussed.