Analog VLSI system for active drag reduction

We describe an analog CMOS VLSI system that can process real-time signals from surface-mounted shear stress sensors to detect regions of high shear stress along a surface in an airflow. The outputs of the CMOS circuit are used to actuate micromachined flaps with the goal of reducing this high shear stress on the surface and thereby lowering the total drag. We have designed, fabricated, and tested parts of this system in a wind tunnel in laminar and turbulent flow regimes.