SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project will address bulk micromachining of single crystal silicon carbide and III-V nitride semiconductors to develop miniaturized fluid density and viscosity sensors based on acoustic wave (AW) principles. Phase I will develop sensors capable of precisely measuring fluid viscosity and density over wide limits under harsh operating conditions: high pressure, high temperature, corrosive, or abrasive. The harsh environments require fabrication of microelectromechanical systems (MEMS) for fluid viscosity-density sensors from silicon carbide (SiC) and gallium-aluminum nitride (GaN-AlN) compounds, which have high melting temperatures (1700-3000 degrees Centigrade) and favorable chemical and mechanical properties. Phase I will test the feasibility of the micromachined SiC-AlN fluid viscosity-density sensors by fabricating an unpackaged pre-prototype device from these materials and demonstrate the measurement of viscosity and density in a variety of fluids at various temperatures and pressures. Harsh-environment MEMS fluid viscosity and density sensors have commercial applications in boreholes for oil exploration and production, monitoring of engine fluids in automobiles, aerospace and military vehicles, and monitoring chemical synthesis and production processes. These devices are expected to increase oil-well production at reduced cost, promote more efficient use of engine fluids resulting from direct and continuous feedback of fluid characteristics, and enable real-time in situ monitoring of chemical processes.

This Small Business Innovation Research Phase II project is aimed at developing MEMS-based miniaturized fluid viscosity and density sensors that can operate within small confines provide electronic readout, and that are capable of surviving harsh environments (high temperature, high pressure, corrosive, abrasive) typical of many fluid sensor applications. The Harsh Environment Fluid Viscosity-Density Sensor consists of a packaged flexural plate wave (FPW) resonator instrumented with low cost, compact electronics for sensor read-out. In Phase I, the technical objectives were successfully accomplished by fabricating resonant FPW fluid sensors from harsh environment compatible single crystal SiC and epitaxial piezoelectric AlN materials, and demonstrated their ability to independently measure fluid viscosity and density. In Phase II, fully functional, packaged and electronically instrumented Harsh Environment Fluid Viscosity-Density Sensor prototypes will be developed and optimized for specific customer applications. The fluid sensors will be field tested in our customer's systems to demonstrate precise and accurate fluid viscosity and density measurements and stable operation in the customer's fluids and environmental conditions. After successful completion of Phase II, the Harsh Environment Fluid Viscosity-Density Sensor will be ready for scale-up manufacturing and commercialization in Phase III.The Harsh Environment Fluid Viscosity-Density Sensor has commercial applications in 1) Condition-Based Maintenance of oils and other fluids in engines and industrial process equipment, 2) Process and Quality Control in manufacturing, chemical processing and water/waste treatment industries, and 3) down-hole sensors for Petrochemical Exploration and Extraction