Complete characterization of a sound field requires measurement of both sound pressure and particle velocity. In this paper, we present a three-dimensional acoustic particle velocity sensor chip. Furthermore, a sound pressure sensor was integrated on the same chip, enabling three-dimensional sound intensity measurements. The integration of multiple sensors on a single silicon chip results in highly reproducible sensors and a very small sensor-to-sensor distance allowing for accurate single-point measurements. The latter is demonstrated by measurement of the 3D particle velocity field of a very small (1 × 1 mm2) sound source.
Yntema, D. R., van Honschoten, J. W., Wiegerink, R. J., & Elwenspoek, M. C. (2008). A complete three-dimensional sound intensity sensor integrated on a single chip. Journal of micromechanics and microengineering, 18(2008/16200/11), 1-9. [10.1088/0960-1317/18/11/115004]. https://doi.org/10.1088/0960-1317/18/11/115004