Facile Fabrication and Integration of Patterned Nanostructured TiO2 for Microsystems Applications

A simple technique to fabricate integrated crack‐free and crystalline nanostructured titania (ns‐titania) in microsystems devices is presented. In this technique, crack elimination is achieved by oxidizing Ti films, pre‐patterned below a threshold dimension, in aqueous hydrogen peroxide solution. Amorphous ns‐titania with walls of pores having thicknesses and pore diameters ranging from 25 nm–50 nm and 50 nm–200 nm, respectively, is formed after oxidation and transformed to anatase after thermal annealing. We demonstrate the functionality of ns‐titania formed and compatibility of this technique with microsystems device manufacturing practices by fabricating a prototype device for gas sensing using integrated ns‐titania features as sensing elements. A facile technique to implement patterned nanostructured titania (ns‐titania) for microsystems applications has been developed (see Figure). An integrated gas sensor utilizing ns‐titania‐pad arrays as sensing elements has been fabricated to demonstrate the compatibility of the proposed technique with microsystems device manufacturing practices.