| Recent applications in vibration measurement, such as on-line machinery health monitoring, place new challenges on the design and fabrication of vibration sensor systems. Micro-Electro-Mechanical-System (MEMS) vibration sensor is small and light, which is the most suitable for the on-line monitoring system and portable equipment. MEMS sensor consumes less power than the traditional sensor due to its smaller size. In addition, MEMS sensor can be batch fabricated to lower the sensor cost dramatically.; In this thesis, five types of MEMS vibration sensor systems are designed. The piezoresistive cantilever sensor and piezoelectric single-beam sensor are designed to detect the Z-axial vibration which is perpendicular to the sensor chip surface. The piezoelectric fish-bone sensor, piezoelectric T-shape sensor, and piezoelectric two-mass sensor are designed to measure the X- or Y-axial vibration which is in the sensor chip plane. We performed both analytical modeling and Finite-Element-Method (FEM) simulation to study the sensor vibration response.; We developed the fabrication process for the piezoresistive and piezoelectric sensors. All the sensors are fabricated successfully. We tested the sensitivity and resonant frequencies of the sensors on the commercial shaker. The test results are analyzed and compared with the design expectation. |
