FET-BASED HYDROPHONE SENSORS

IN THE COURSE OF THEIR WORK IN MICROSENSORS, MICROACTUATORS, AND ROBOTICS, SRC AND ITS ASSOCIATES HAVE DEVELOPED A NUMBER OF UNIQUE FIELD-BASED SENSORS UTILIZING FIELD EFFECT TRANSISTORS (FETS). BECAUSE THESE SENSORS EXHIBIT HIGH SENSITIVITY AND EXCELLENT LOW FREQUENCY RESPONSE AND AFFORD THE POSSIBILITY OF DIGITAL OUTPUT SIGNALS, THEY OFFER ADVANTAGES OVER CONVENTIONAL PIEZOELECTRIC OR FERROELECTRIC ELEMENTS IN HYDROPHONES, WHICH PRESENTLY HAVE LIMITED LOW-END FREQUENCY RESPONSES WITH ANALOG OUTPUTS. MICROFABRICATION PRINCIPLES CAN BE APPLIED TO MAKE THE PROPOSED FET SENSORS SMALL, RELATIVELY INEXPENSIVE, AND IN LARGE QUANTITIES. THE PROPOSED FET SENSORS CAN ALSO BE NETWORKED INTO VERY LARGE HYDROPHONE ARRAYS VIA MULTIPLEXING CIRCUITRY ON THE FET SENSOR CHIP, ENABLING EFFICIENT DISTRIBUTED SURVEILLANCE THROUGHOUT THE OCEANS. THIS PROPOSAL WILL INVESTIGATE THE SUITABILITY OF FET-BASED MICROSENSORS FOR A NUMBER OF HYDROPHONE-RELATED APPLICATIONS, WITH PARTICULAR ATTENTION TO BANDWIDTHS, SENSITIVITIES AND RESOLUTIONS OF THESE DEVICES. THE PROPOSED PHASE I RESEARCH CONSISTS OF SYSTEM ANALYSIS, PRELIMINARY SENSOR AND PACKAGING DESIGNS, FUNDAMENTAL EXPERIMENTATION, AND FABRICATION PROTOCOLS FOR FET-BASED HYDROPHONE ELEMENTS. FET-BASED HYDROPHONES WOULD OPEN UP AN IMPORTANT APPLICATION AREA IN THE RAPIDLY EXPANDING MICROELECTROMECHANICAL SYSTEMS FIELD, AND WOULD PROVIDE A TECHNOLOGY PUSH AND EDGE IN THE HYDROPHONE AREA SO CRUCIAL TO NAVAL MONITORING EFFORTS. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - BENEFITS: SIGNIFICANTLY ADVANCE THE STATE OF THE ART OF A VERY DEMANDING APPLICATION, NAMELY, HYROPHONE ACOUSTIC DETECTION SYSTEMS. APPLICATIONS: HIGH SENSITIVITY, HIGH RESOLUTION, ACOUSTIC DETECTION SYSTEMS, INCLUDING HYDROPHONES.