Research On SU-8 Photoresist Fiber Optic Accelerometer Sensor

More and more sensing devices, with a strong anti-electromagnetic interference ability, high sensitivity, wide dynamic range, and reusability, are in badly need in many industrial fields, especially in some special application areas like the structure detection system of bridge building, traffic monitoring system, seismic detection system of oil exploration, aerospace guidance system and so on. Own to its excellent performances, that high sensitivity, small size, reusability, and anti-electromagnetic interference, the accelerometer based on the fiber sensing technology becomes a research focus of industrial production and national defense construction. The fiber accelerometer studied here is an improvement of the current acceleration sensing technology. It may present a solution to microminiaturization and batch production, and provide a theoretical basis and a simulation proof for the studies of pressure, temperature, strain, vibration, liquid level or flow sensor applied in petrochemical industry and aviation.A kind of Fabry-Perot fiber optical acceleration sensor based on SU-8photoresist is designed. A beams-mass structure is made by using the SU-8photoresist’s high aspect ratio processing technology, which is sensitive to the acceleration. Theoretical expressions are deduced for analyzing the relation between acceleration and the beams-mass structure’s deflection, and the Fabry-Perot interference light intensity. Simplified calculation formulas are obtained. Major influences on the sensitivity and the natural frequency and damping are discussed. The beams-mass structure in the "卍" form is presented, whose parameters have been confirmed after analyzing and simulating. The producing steps of the accelerometer are explored. The simulation results match to the theoretical analysis, which shows that the sensitivity of the accelerometer in the "卍" structure has been improved vastly, and it can sense monitoring acceleration in real time by using Fabry-Perot interference theory.A kind of Fabry-Perot fiber optical acceleration sensor based on the hollow core fiber is developed. It is made by fusing commercial single fiber and hollow core fiber. The principles of the optical fiber sensor based on Fabry-Perot interference theory and spring-mass system, are discussed. The relation between the sensing performance and the mass, and the different cavity radius is deduced, and its parameters are obtained. The good sensing performance and advantages of the designed accelerometer are demonstrated through the theoretical analysis and simulation. It is cabinet, simple for fabrication.