5 April 2006 Modeling and optimization of a side-implanted piezoresistive shear stress sensor
Author Affiliations +
This paper presents the modeling and design optimization of a micromachined floating element piezoresistive shear stress sensor for the time-resolved, direct measurement of fluctuating wall shear stress in a turbulent flow. The sensor structure integrates side-implanted diffused resistors into the silicon tethers for piezoresistive detection. A theoretical nonlinear mechanical model is combined with a piezoresistive model to determine the electromechanical sensitivity. Lumped element modeling (LEM) is used to estimate the resonant frequency. Finite element modeling is employed to verify the mechanical models and LEM results. Two dominant noise sources, 1/f noise and thermal noise, were considered to determine the noise floor. These models were then leveraged to obtain optimal sensor designs for several sets of specifications. The cost function is the minimum detectable shear stress that is formulated in terms of sensitivity and noise floor. This cost function is subjected to the constraints of geometry, linearity, bandwidth, power and resistance. The results indicate the possibility of designs possessing dynamic ranges of greater than 85dB.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yawei Li, Yawei Li, Melih Papila, Melih Papila, Toshikazu Nishida, Toshikazu Nishida, Lou Cattafesta, Lou Cattafesta, Mark Sheplak, Mark Sheplak, } "Modeling and optimization of a side-implanted piezoresistive shear stress sensor", Proc. SPIE 6174, Smart Structures and Materials 2006: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, 617409 (5 April 2006); doi: 10.1117/12.658029; https://doi.org/10.1117/12.658029

Back to Top