High Accuracy, Low Cost, Absolute Pressure Transducer

A compact, low cost, and high accuracy very low pressure gauge is needed by the Air Force to reduce the cost of testing aircraft parts in hypersonic flow. A wide variety of gauges exist to sense the pressure of gases in specific pressure ranges rangingfrom vacuum to thousands of pounds per square inch. However, not many gauges exist that can measure accurately in a large pressure range, and fewer still can make any claims of accuracy.SiWave proposes to develop a MEMS based pressure transducer for very low pressure levels in hypersonic wind tunnels. Most currently available pressure sensors use a MEMS diaphragm with piezoresistive elements to sense its deflection and have limitedaccuracy at low pressures. The proposed pressure sensor utilizes a micromachined resonator, and offers the highest accuracy at low pressures.SiWave has teamed with a leader in pressure sensor technology to evaluate and commercialize its sensors for both DoD and commercial applications. This development will lead to a lower cost sensor that will improve accuracy over current sensors by a factor of five. The proposed device has applications in the military, commercial aeronautics, automotive, and consumer products. Markets for thistechnology include altimetry, aircraft air speed measurement, automotive emissions control, and vacuum sensing. The total size for the pressure sensor market is over $1 billion per year. In automotive applications, for example, tens of millions of manifoldabsolute pressure (MAP) and barometric absolute pressure (BAP) sensors are sold each year and are found in most passenger vehicles. Our first product will be an ultra-small high-accuracy pressure sensor designed for wind tunnel and other military aircraftapplications.