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

This paper outlines the integration of single crystal piezoelectric materia ls having high piezoelectric coefficients, with a novel method of strain am plification in a flexural-type accelerometer. The latter utilizes a sensing structure comprised of a bending plate that has a castellated surface, whi ch raises the piezoelectric sensing material that is mounted there: above i ts neutral axis. This device is called a platformed unimorph accelerometer (PUMA (TM)). The castellated height is adjusted depending upon the electrom echanical properties of the sensing material, and it amplifies the stress i n 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 flo or. (C) 2001 Elsevier Science B.V. All rights reserved.