The development of high-sensitivity, low-noise accelerometers utilizing single crystal piezoelectric materials

Abstract This paper outlines the integration of single crystal piezoelectric materials having high piezoelectric coefficients, with a novel method of strain amplification in a flexural-type accelerometer. The latter utilizes a sensing structure comprised of a bending plate that has a castellated surface, which raises the piezoelectric sensing material that is mounted there above its neutral axis. This device is called a platformed unimorph accelerometer (PUMA™). The castellated height is adjusted depending upon the electromechanical properties of the sensing material, and it amplifies the stress in the crystal and generates a higher charge output. Accelerometer noise is inversely proportional to charge output, especially at low frequencies. As a result, the new accelerometer exhibits a 15 dB reduction in its noise floor.