Effect of dynamic pressure on direct shear stress sensor design

TitleEffect of dynamic pressure on direct shear stress sensor design
Publication TypeConference Paper
Year of Publication2010
AuthorsChandrasekharan, V., J. Sells, D. P. Arnold, and M. Sheplak
Conference Name48th AIAA Aerospace Sciences Meeting, AIAA Paper 2010-004
Date Published01/2010

A microelectromechanical systems (MEMS)-based capacitive floating element shear stress sensor, developed for time-resolved turbulence measurement, is studied for its response to unsteady pressure forcing. The floating element structure incorporates interdigitated comb fingers forming differential capacitors, which provide electrical output proportional to the floating element deflection. An equivalent circuit model is provided under simultaneous pressure and shear loading. A design strategy to mitigate pressure sensitivity while enhancing shear stress sensitivity is provided. The significance of the design methodology is experimentally illustrated via comparison of combined shear and pressure response of the sensor with its pressure response. Results indicate a significant effect of pressure on combined sensor response despite 64 dB of pressure rejection.