Monolithic Multiple Degree of Freedom Micromachined Inertial Sensors for Structure Monitoring

Recent advances in microfabrication technology enable us to build monolithic multiple axis inertial sensors (MMAxIS) with response from DC to several kilohertz. Because NMAxIS devices are physically very small (less than 1 cubic centimeter, including readout electronics) and are constructed monolithically, using a single piece of silicon, they are very rugged, capable of withstanding high pressures and continuous accelerations in excess of 40,000g. Small size also leads to low electrical power consumption. We propose to design and fabricate a batch of NMAxIS devices under Phase I, using low-cost commercial silicon foundry services. Scientists at Tanner Research, Inc. have designed, fabricated, and tested a variety of micromachined devices, including sensors fabricated using the process we propose to use for NMAxIS. With our demonstrated expertise in both electronic design and microelectromechanical systems (MEMS), we are well- qualified to design, build, and demonstrate a very compact, rugged inertial measurement unit based on MMAxIS. During the option period, we will test the structures that were designed and fabricated under the initial portion of the Phase I effort. The- test results will provide a springboard into Phase II research, allowing us to proceed to refine the first- pass NMAxIS structures into second-generation designs ready for fabrication at the start of Phase II. During Phase II we will demonstrate a small structure-sensing network incorporating MMAxIS inertial sensing. Phase III will see the development of a production device suitable for full-scale structural instrumentation.