Small Business Innovation Research/Small Business Tech Transfer
MEMS Skin Friction Sensor
Project Description
Interdisciplinary Consulting Corporation proposes a sensor that offers the unique capability to make non-intrusive, direct, simultaneous mean and fluctuating shear stress measurement for subsonic and transonic test applications. Currently a standard for shear stress measurement tool does not exist. A precise silicon micromachined, differential capacitive, instrumentation grade sensor will facilitate skin friction measurement with high bandwidth, high resolution, and minimal sensitivity to pressure. The proposed sensor possesses through wafer vias for backside electrical contacts to enable non-intrusive measurements in turbulent boundary layers. A robust and compact package with miniature interface electronics enables flush sensor mounting conformal with surfaces. The sensor development effort transitions a proof-of-concept device by adding design components to have reduced pressure sensitivity to result in a commercially viable product. Circuit topology development for biasing and signal conditioning provides the ability to make simultaneous mean and dynamic shear stress measurement. The sensor performance will exceed its predecessors and set the standard for quantitative skin friction measurements. The simplicity of sensor design and an equally simple and proven fabrication technique allows for low cost, high performance sensors. The sensor holds promise to transform current flow control techniques and enable efficient aerodynamic designs. Existing shear stress estimation techniques rely on known correlation to a measured quantity. Direct measurement eliminates the need for a known correlation in an unknown flow. Capacitive transduction has been successful for a highly sensitive device with a large dynamic range and low noise floor, which is the current state of the art. The proposed sensor may therefore be improved beyond the state of the art to serve as a measurement standard for all types of skin friction measurement techniques.
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Anticipated Benefits
Several research institutes and aviation companies perform routine wind tunnel testing in the subsonic and transonic regimes. Formula 1 cars undergo aerodynamic design changes on a weekly basis and are tested at full scale in wind tunnels. With depleting petroleum reserves, wind turbines are being increasingly utilized, necessitating blade/vane design and material improvements for better efficiency. Wind turbine control is increasingly implemented in wind farms for power regulation using turbine pitch and yaw control techniques where skin friction measurement may serve as a feedback signal. In 2008 alone the wind energy industry attracted over $17 billion indicating substantial amount would be invested in control system, which is a portion of the 34% of the wind turbine cost. Skin friction measurement is extremely important for advancements in all of these applications. Shear stress may also be used to estimate flow rate, which opens the $1.35 billion flow rate sensor market for non-intrusive measurements. For example, remote flow rate monitoring in transcontinental pipelines for transporting natural gas and other hydrocarbon fuels. This sensor may also serve as a platform technology with a potential impact on a broad application spectrum that ranges from fundamental scientific research to industrial process control, biomedical applications, etc.
Simultaneous mean and dynamic shear stress measurement will enable NASA ATP facilities to precisely measure wall skin friction, which is currently not possible. Specifically, in the subsonic and the transonic regimes, this sensor will allow NASA ATP to explore skin friction drag reduction technology. This capability provides scientific value and poses significant commercial gain to NASA ATP by means of providing aerodynamic design and testing opportunity to the aviation industry. Furthermore, this technology enables NASA to establish a primary calibration standard for other shear stress measurement techniques, potentially extending this capability to supersonic and hypersonic regimes. Specific NASA ATP facilities that will benefit from precise skin friction instrumentation for aerodynamic performance estimation are: NASA Glenn Research Center: 9' by 15' low speed wind tunnel NASA Langley Research Center: 14' by 22' Subsonic Wind Tunnel, 20 Foot Vertical Spin Tunnel, and the 11 ft x 11 ft Transonic Unitary Plan Facility. The silicon micromachining technique inherently minimizes unit cost. Overall, NASA and the aviation industry stand to significantly benefit via better aerodynamic design and higher efficiency/ lower drag at lower cost. More »
Simultaneous mean and dynamic shear stress measurement will enable NASA ATP facilities to precisely measure wall skin friction, which is currently not possible. Specifically, in the subsonic and the transonic regimes, this sensor will allow NASA ATP to explore skin friction drag reduction technology. This capability provides scientific value and poses significant commercial gain to NASA ATP by means of providing aerodynamic design and testing opportunity to the aviation industry. Furthermore, this technology enables NASA to establish a primary calibration standard for other shear stress measurement techniques, potentially extending this capability to supersonic and hypersonic regimes. Specific NASA ATP facilities that will benefit from precise skin friction instrumentation for aerodynamic performance estimation are: NASA Glenn Research Center: 9' by 15' low speed wind tunnel NASA Langley Research Center: 14' by 22' Subsonic Wind Tunnel, 20 Foot Vertical Spin Tunnel, and the 11 ft x 11 ft Transonic Unitary Plan Facility. The silicon micromachining technique inherently minimizes unit cost. Overall, NASA and the aviation industry stand to significantly benefit via better aerodynamic design and higher efficiency/ lower drag at lower cost. More »
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Interdisciplinary Consulting Corporation | Lead Organization | Industry | Gainesville, Florida |
Langley Research Center
(LaRC)
|
Supporting Organization | NASA Center | Hampton, Virginia |
Primary U.S. Work Locations
-
Florida
-
Virginia
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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.