Take Direct Measurements of Shear Stress

Aerospace engineers and aerodynamicists designing next-generation vehicles have had to rely on uncertain correlations to estimate wall shear stress — until now. Building on two decades of research and rigorous testing, IC²'s DirectShear™ sensors measure wall shear stress directly to deliver an unprecedented degree of precision and accuracy for both mean and fluctuating measurements with best-in-class bandwidth and dynamic range.

IC²’s time-resolved, direct measurement approach ensures accurate measurements without disturbing the flow or requiring a unique calibration between heat transfer and shear stress. Our technology directly measures the wall shear stress through a micromachined, MEMS floating element via either capacitive or optical readout.  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, high-temperature flow sensing and control
  • Propulsion system and engine health management

Features and 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

IC² offers two main types of shear stress sensors using either capacitive or optical transduction.  This versatility ensures optimal operation in a target environment, maximizing performance while meeting challenging application requirements.

DirectShear

DirectShear system direct shear stress sensor.jpgDirectShear™ sensors are robust, high-bandwidth, high-resolution, silicon-micromachined differential capacitive shear stress sensors for subsonic and transonic applications. This non-intrusive design delivers an unprecedented degree of precision and accuracy for both mean and fluctuating wall shear stress measurements.  This sensor system greatly extends the spatial and temporal resolution capabilities over existing devices, offering best-in-class bandwidth and dynamic range.

Originally developed for and funded by NASA, DirectShear™ capacitive sensors are now commercially available and are ideal for precise skin friction measurements in wind tunnels.

Learn More

DirectShear-OpticalDirectShear Optical enables mean and fluctuating skin friction measurements at high temperatures.

Extreme environments call for extreme materials and innovative designs. IC² now offers an optical micromachined shear stress sensor, designed for high-temperature shear stress measurement applications.  Similar in structure to the standard capacitive DirectShear™ sensors, the optical versions instead use a floating element made from silicon/Pyrex (for high temperatures) or sapphire (for ultra-high temperatures) 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 DirectShear™ optical sensors all use a differential grating pattern to increase sensitivity and resolution while minimizing cross-axis sensitivity to pressure.

Learn More