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 direct, non-intrusive, simultaneous mean and fluctuating wall shear stress measurements, ideal for precise skin friction measurements in wind tunnels.  The shear stress sensor offers best in class performance with high bandwidth, dynamic range and accuracy.

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.

Download DirectShearTM Brochure


  • Micromachined floating element shear stress sensor that enables time-resolved, one-dimensional, direct
    shear stress measurements
  • Compact, robust sensor package for flush mounting
  • Optimized Sensor Control Unit (SCU) for high dynamic range and bandwidth
  • Suite of sensor models for different applications
  • Originally developed for and funded by NASA


  • Instrumentation-grade skin friction sensing
  • Aerodynamic drag research
  • Detection of flow separation
  • Wind tunnel instrumentation


  • Direct measurement of shear stress – no heat transfer calibration
  • Non-intrusive – minimal flow disturbance
  • Simultaneous mean and fluctuating shear stress measurements
  • High resolution, dynamic range and bandwidth
  • Highly accurate, quantitative measurements

Image of the shear stress sensor control unit (SCU-100) for the DirectShear Sensing System

The DirectShearTM Sensor Control Unit (SCU) enables mean and fluctuating measurements when paired with a capacitive sensor.

Sensor Control Unit (SCU)

Download SCU-100 Datasheet

  • Integrated analog synchronous modulation/demodulation system
  • Enables mean and fluctuating measurements using a capacitive sensor, e.g., wall shear stress or pressure
  • Provides low-noise power to sensor head and conditions analog voltage signal for output to a DAQ
  • SCU provides sensor bias voltages
  • Available in AC/DC, AC only models

Key Features 

  • Mean and fluctuating capacitive sensor measurements
  • Selectable low-noise AC or rechargeable Li-ion battery power source
  • LED status indicators
  • 6-pin shielded sensor connector

Close up image of a shear stress sensor sensing head for the DirectShear Sensing System

The capacitive sensor head features backside contacts for minimal flow disturbance.

Sensing Heads

  • Micromachined, floating element device that enables time-resolved, 1-D, direct mean and fluctuating wall shear stress measurements
  • Sensor installed in a cylindrical stainless steel housing
  • Custom housings/materials available
  • Non-intrusive – minimal flow disturbance
  • Removable 6-pin shielded sensor cable
  • Shoulder and key for precision alignment


Available DirectShear Sensor Models

Click model # for datasheet