A metal-on-silicon differential capacitive shear stress sensor

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 Gt 102 dB and a noise floor of 14.9 muPa/radic(Hz) at 1 kHz , outperforming previously reported sensors by nearly two orders of magnitude in MDS.