A Metal-On-Silicon Differential Capacitive Shear Stress Sensor

TitleA Metal-On-Silicon Differential Capacitive Shear Stress Sensor
Publication TypeConference Paper
Year of Publication2009
AuthorsChandrasekharan, V., J. Sells, J. Meloy, D. P. Arnold, and M. Sheplak
Conference NameTech. Dig. 15th Int. Conf. Solid-State Sensors, Actuators, and Microsystems (Transducers 2009)
Date PublishedJune
Conference LocationDenver, CO

The paper presents a direct, capacitive shear stress sensor with performance sufficient for time-resolved turbulence measurements. The device employs a bulk-micromachined, metal-plated, differential capacitive floating-element design. A simple, two-mask fabrication process is used with DRIE on an SOI wafer to form a tethered floating element structure with comb fingers for transduction. Experimental results indicate a linear sensitivity of 7.66 mV/Pa up to the testing limit of 1.9 Pa at a bias voltage of 10 V, and a bandwidth of 6.2 kHz. The sensor possesses a dynamic range >102 dB and a noise floor of 14.9 micro-Pa/rtHz at 1kHz, outperforming previously reported sensors by nearly two orders of magnitude in MDS.