Reliability is a major challenge for the successful exploitation of MEMS technology. ' This thesis presents a systematic taxonomy of typical failure modes and effects in MEMS. The failures are classified according to their occurrence: manufacturing, operation, environmental effect and package related effect. To prioritise these failures, a systematic proactive Failure Mode and Effect Analysis (FMEA) is presented as a tool to be used concurrently in the design phase. The FMEA is successfully applied on a MEMS flexure electrothermal actuator. The FMEA study identified the key issues affecting the reliability of the considered actuators and provided val,uable recommendations to improve their functional performance, efficiency and reliability. Particular emphasis is put on the failure modes of the micro electrothermal flexure actuator and the corresponding failure mechanisms are presented. A high-level functional behavioural modelling methodology for fast and flexible modelling of multiphysical MEMS functional behaviour is presented using the VHDL-AMS language. In particular a high level behavioural model is described for the functional displacement of the electrothermal flexure actuator. Moreover, using the same approach a theoretical study of the performance is presented in the case of the electrothermal flexure actuator at low pressure and high temperature ambient conditions. Practical testing of the effects of low ambient pressures and high ambient temperatures on the performance and reliability of the thermal actuators has been performed. The test results are compared successfully with the results of the thermal actuators high level performance model to assess the validity and accuracy ofthe models.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:490960 |
| Date | January 2008 |
| Creators | Lavu, Srikanth |
| Publisher | Heriot-Watt University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10399/2053 |
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