This design project was undertaken in an interdisciplinary group of eight mechanical and electrical engineers. The objective was to design and analyse a MEMS (microelectromechanical systems) vibration sensor for use in jet engine vibration detection, to meet the specifications detailed by a customer. My task focused on the micro mechanical design of the device, and ensuring the feasibility of the design and continuing adherence to specifications through efficient collaboration and communication between different subgroups.

The final system measured engine vibrations through the displacement of the capacitive comb fingers of the MEMS accelerometer. The output from the mechanical system was translated to an appropriate voltage via an electrical read-out circuit. In order to ensure the best-performing mechanical design, I was responsible for various aspects like:

  • ​Vibration modelling of the proof mass and fingers.
  • Analysing micro-scale damping caused by friction with surrounding air particles.
  • Designing folded flexure beams to achieve a suitable stiffness.
  • Investigating the common failure mechanisms like voltage pull-in and substantial finger bending.
  • Conducting Finite Element Analysis (FEA) of the structure and comparing it with theoretical predictions.
  • Generating a MATLAB script to iterate through different designs of the sensor and evaluating their performance.