In-Cylinder Micromachined Pressure Transducers

Increasingly strict emissions requirements and the need to increase fuel economy and reduce service intervals have dramatically accelerated the use of monitor and control electronics in engines. traditional methods such as adjusting the air/fuel ratio to optimize catalyst performance are not effective enough to meet future requirements. Measurement of the pressure in each cylinder permits enhanced control of engine operation which results in decreased exhaust emissions and improved fuel efficiency. A large and growing percentage of sensors are being replaced by micromachined silicon sensors but their operating temperature range is typically O < T < 125 C; silicon-based devices are inherently unsuitable at high temperature. Silicon carbide sensors and control electronics can potentially operate at temperatures approaching 1000 c or in harsh invironments. ATMI has successfully developed a novel surface SiC micromachining technology applicable to the manufacture of a cost-effective in-cylinder pressure measurement system for automotive use. In Phase I we will fabricate a prototype pressure transducer. In Phase II we will optimize the transducer design and integrate a small preamplifier on the same chip as the sensor. Phase II development and Phase III commercialization will be performed in collaboration with major automotive manufacturers.