AN EAR-INSPIRED SOUND PRESSURE AMPLIFICATION STRUCTURE FOR FABRY-PEROT ACOUSTIC SENSOR

In this paper, inspired by the ossicular chain in human middle ear, a miniature sound pressure amplification structure (SPAS) based on double 10 mu m-thickness E-shaped steel diaphragms with the corresponding diameters of 15 mm and 3 mm was developed to enhance the sensitivity of diaphragm-type Fabry-Perot (F-P) acoustic sensor. FEM simulation demonstrated the availability of the SPAS in terms of the achieved acoustic field response within a certain frequency range. Then acoustic test showed that the F-P acoustic sensor using a silver diaphragm, adapted with the developed SPAS, achieved a remarkable sensitivity amplification ratio of up to similar to 7.6 in the range of 1.5 similar to 2.1 kHz, which can be further widened by optimizing structure dimensions and membrane materials.