Design and microfabrication of biomimetic acoustic pressure gradient sensitive structure

The principle of the directional hearing of the parasitoid fly ormia ochracea was introduced. Inspired by the flyś mechanically coupled eardrums, a novel MEMS directional biomimetic acoustic pressure gradient sensitive structure was designed. The analytic formulae describing the relationship between the resultant moment of incoming plane wave acting on the structure and the acoustic pressure gradient, structural parameters were derived. A microfabrication process of the sensitive structure was proposed based on silicon on insulator ( SOI ) wafer. Process parameters of the key fabrication steps such as step photolithography, SOI wafer-glass anodic bonding, handle wafer and buried silicon dioxide removal using wet etching were also decided. The fabrication result has proved that the sensitive structure which has three-dimensional scale can be achieved using bulk micromaching.