The ability to pattern oxide structures at the micro and nano scale in both planar and three-dimensional forms is important for a broad range of emerging applications such as in the development of sensors, micro-fuel cells and batteries, photocatalysts, solar arrays and photonic band gap (PBG) materials. Several techniques have recently been introduced for patterning materials, including colloidal self-assembly, holographic lithography, and direct laser and ink writing approaches. Unfortunately, these approaches are mainly confined to polymeric systems that lack the specific functionality required for a given application. The earlier efforts for 3D printing were based on polyelectrolyte inks that required a reservoir-induced coagulation without much control over deposition process. But now sol-gel inks techniques enable the direct ink writing (DIW) of functional oxides at the micro and nano scale. DIW is a layer-by-layer assembly technique in which materials are fabricated in arbitrary planar and 3D forms with lateral dimensions that are two orders of magnitude lower than those achieved by ink-jet printing. The concentrated inks can be created and extruded through fine deposition nozzles as filament(s), and subjected to undergo rapid solidification to maintain their shape even as they span gaps in underlying layer(s). These new inks can be directly printed in air providing exquisite control over the deposition process (e.g., the ink flow can now be started/stopped repeatedly during assembly).