MEMS-based probes for velocity and pressure measurements in unsteady and turbulent flowfields

This work presents our progress in the development of MEMS-based, high-performance, fast-response, multi-sensor pressure probes of miniature size for velocity and pressure measurement in unsteady and turbulent flowfields. The fabrication and calibration (theoretical and experimental) of miniature (order of 1mm in diameter) 5-sensor hemispherical-tip probes, are discussed. The first stages of the development process have been to fabricate a sensitive MEMS pressure sensor and to develop calibration algorithms and environments for fast-response probes. We fabricated first-generation bossed-diaphragm absolute pressure sensors 100×100 μm² in size. One of the challenges in the pressure sensor development is the design of sensors with sensitivity sufficient for accurate measurements in flow conditions most commonly of interest to the scientific and industrial community. New probe calibration techniques are introduced. Both theoretical and experimental approaches are employed to develop calibration techniques suitable for unsteady and turbulent flow environments with fine time and length scales.