| Summary: | 碩士 === 國立臺灣大學 === 應用力學研究所 === 100 === Nowadays the acceleration switch, a special type of accelerometer, has become one of peculiar sensing devices. As the acceleration reaches a threshold, the switch turns into locked state, and the contact components export a signal which can trigger the subsequent action. In recent years, rapid progressive technologies enable micro-nano electro-mechanical systems (MEMS) to develop more sophisticated functionality. Modern MEMS not only reduce the cost and scale, but also improve the reliability and the measuring range of accelerations. The products penetrate into many major businesses, such as home care systems, smart phones, amusement equipment, in addition to the traditional automotive industry, aerospace and defense industries.
In this thesis, we aimed to design acceleration switches which are applicable to the impact of high-G environment. In order to reduce research cost and time, we utilized computer assisted design (CAD) software to create models, then imported to computer assisted engineering (CAE) software for dynamic simulation. From the analysis results, we validated that the G-switches can function well to fulfill the impact specifications of MIL-STD 883E conditions. As the accelerations reach their respective thresholds, the latch mechanism was successfully locked up, the contact elements delivered the touched signal, and materials of the switches did not damaged. Based on the simulation results, we employed MEMS processing technology to fabricate our designs of acceleration switches on SOI wafers. Upon cutting and simple packaging, the switches were examined on a centrifugal machine which was adjusted to specific acceleration levels. The tests proved that all acceleration switches were satisfactorily manufactured and functioned properly to meet the severe impact conditions. The latched mechanism could be quickly released by applying 1V DC power to the releasing device. This thermally releasing device allows the acceleration switch to reuse again.
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