Take Direct Measurements of Shear Stress

Image of the DirectShear Sensing System including the shear stress sensor control unit (SCU-100) and one of our sensing heads.

IC²’s DirectShearTM Sensing Systems enable non-intrusive, direct, simultaneous mean and fluctuating wall shear stress measurements.

Existing thermal shear stress sensors use an indirect technique that infers a wall shear stress from a measured heat transfer.  This approach severely limits the accuracy and greatly increases the uncertainty for quantitative measurements.   In contrast, IC²’s time-resolved, direct measurement approach ensures accurate measurements without disturbing the flow and without requiring a unique calibration between heat transfer and shear stress. Our technology directly measures the wall shear stress through a micromachined, MEMS floating element and either a capacitive or optical transduction method.  This approach bypasses the limitations of existing devices, significantly improving accuracy and reducing uncertainty.

Applications

  • Instrumentation-grade skin friction sensing
    • Aerodynamic drag characterization
    • Fundamental research
  • Detection of flow separation
  • Wind-tunnel instrumentation
  • Non-intrusive and high temperature flow sensing and control
  • Propulsion system and engine health management
Image of our latest shear stress sensor sensing head for the DirectShear Sensing System.

Our latest shear-stress sensing head for the DirectShearTM Sensing System features a removable 6-pin shielded cable.

Features/benefits

  • Time-resolved, direct measurement of wall shear stress
  • Non-intrusive → does not disturb the flow
  • Capable of mean and fluctuating measurements
  • High resolution and dynamic range
  • Highly accurate, quantitative skin friction measurements
  • Small sensor size → high spatial resolution

Products

DirectShearTM Sensing Systems

IC² now offers a robust, high-bandwidth, high-resolution, silicon micromachined differential capacitive shear stress sensor for subsonic and transonic applications. This innovative design enables non-intrusive, simultaneous mean and fluctuating wall shear-stress measurements,  ideal for precise skin friction measurements in wind tunnels.  This sensor system greatly extends the spatial and temporal resolution capabilities over existing devices as well as the overall accuracy of skin friction measurement technology.

Image of our silicon shear stress sensor die for our DirectShear Sensing System.

The shear stress sensor die contains all backside electrical contacts for minimal flow disturbance.

Originally developed for and funded by NASA, the capacitive sensors are now commercially available.  Contact us now to get more information, place an order or discuss how we can customize this product for special applications.

  • High bandwidth, dynamic range and spatial resolution 
  • Compact, robust sensor packaging with backside contacts for flush mounting
  • Optimized interface circuitry for high dynamic range and bandwidth
  • Non-intrusive, mounts flush to test models & wind tunnels for minimal flow disturbance and impact 
  • Suite of sensor models for different applications

Optical Shear Stress Sensors

This is a shot of our standard temperature optical shear stress sensor, highlighting the sensing head, fiber array and MPO connector.

This is a shot of our standard temperature optical shear stress sensor, highlighting the sensing head, fiber array and MPO connector.

Extreme environments call for extreme materials and innovative designs. IC² is developing an optical micromachined shear stress sensor, designed for high-temperature shear stress measurement applications.  Using a silicon/pyrex (for high temperatures) or a sapphire (for ultra-high temperatures) floating element and a high-temperature optical fiber readout for remote measurement, the technology enables high accuracy, time-resolved skin friction measurements directly in harsh environments without any disturbance to the flow. Our optical sensors all use a geometric moire transduction technique to increase sensitivity and resolution while minimizing cross-axis sensitivity to pressure.

  • Standard, high temperature (up to 700K) and ultra-high temperature ( up to 1200K) versions available
  • Remote sensor readout via optical fibers for immunity to EMI 

     

    Image of our ultra-high temperature capable shear-stress sensors using sapphire sensing heads and sapphire optical fibers.

    IC² is developing ultra-high temperature capable shear-stress sensors using sapphire sensing heads and sapphire optical fibers.

    Contact us now to get more information, reserve yours or to discuss how we can customize this product to meet your unique needs.