RESONANT BEAM SILICON ACCELEROMETERS

THIS PROPOSAL IS TO ANALYZE A NEW MICROMECHANICAL STRUCTURE FOR THE PRECISION MEASUREMENT OF ACCELERATION. THE DEVICE UTILIZES A HIGH Q SILICON RESONATOR INCORPORATED INTO THE SILICON HINGE OF A MONOLITHIC SILICON ACCELEROMETER. RESONATORS HAVE THE POTENTIAL OF OFFERING TRULY EXCEPTIONAL STABILITY AT VERY LOW COST AND WITH ONLY MINOR ADDITIONAL PROCESSING COMPLEXITY OVER WHAT IS NEEDED CURRENTLY. RESONANT BEAM STRUCTURES HAVE BEEN FABRICATED FOR A NUMBER OF PRESSURE SENSOR APPLICATIONS TO DEMONSTRATE EXPERIMENTAL FEASIBILITY. THIS WORK WILL BUILD UPON THE PRESSURE SENSINGTECHNOLOGY INTO A SELF-CONTAINED SILICON ACCELEROMETER STRUCTURE; AS SUCH, THIS PROJECT DOES NOT REPRESENT A PROVENCONCEPT NOR IS IT A TRIVIAL EXTENSION OF THE EXISTING TECHNOLOGY. PHASE I WOULD BE THE INITIAL PROJECT WHEREIN THE BASIC DESIGN ISSUES ARE ADDRESSED. THE INTENTION IS TO INVESTIGATE THE PROBLEMS ASSOCIATED WITH IMPLEMENTING THIS TECHNOLOGY FOR ACCELEROMETER APPLICATIONS. THE SPECIFIC DEVICE HAS BEEN CHOSEN AS A VEHICLE TO BETTER UNDERSTAND THEPHYSICAL LIMITATION IN THE DESIGN OF RESONANT BEAM STRUCTURES. CONCERNS INCLUDE: RESONATOR DESIGN, TRANSDUCTION EFFICIENCY, MECHANICAL STRUCTURE DESIGN, LOW PROCESS COMPLEXITY, SIGNAL PROCESSING. EACH OF THESE MERGESFUNDAMENTAL SCIENCE WITH APPLIED ENGINEERING. THE KNOWLEDGEREGARDING SILICON MICROSTRUCTURES IS STILL SUFFICIENTLY LIMITED THAT PROPERTIES OF MATERIALS, STRUCTURAL LIMITATIONSDUE TO SILICON ETCHING, AND THE PRACTICAL IMPLEMENTATION OF THE DESIGN ALL EFFECT PERFORMANCE. THE PURPOSE IS THREE FOLD. PRIMARILY, IT IS A STUDY OF RESONANT BEAM TRANSDUCTION APPROACHES IN A HIGHLY SENSITIVE SILICON STRUCTURE TO OBTAIN A BASIC UNDERSTANDING OF THE TRANSDUCTION PRINCIPALS, PERFORMANCE, AND LIMITATIONS. SECOND, IT WILL FOCUS ON A TECHNOLOGY WHICH SHOULD COMPLEMENT BOTH CONVENTIONAL SILICON PIEZORESISTIVE AND DISCRETE SINGING WIRE ACCELEROMETERS. THIRD, IN THE LONG TERM, THE DEVICE PROMISES TO SERVE AS A VERY LOW POWER, DIGITALLY COMPATIBLE TRANSDUCTION APPROACH WHICH CAN OPEN UPMAJOR NEW MARKETS IN MEDICAL, AUTOMOTIVE, MILITARY/AEROSPACEAND INDUSTRIAL CONTROL.