Dynamic and Static CoDesign Methodology and Realization of Piezoresistive Pressure Sensors
Mehmet Akif Ozkaya
Electronics Engineering, MSc Thesis, 2026
Thesis Jury
Asst. Prof. Korkut Kaan Tokgöz (Thesis Advisor)
Prof. Ayhan Bozkurt
Assoc. Prof. Yiğit Dağhan Gökdel
Date & Time: June 22th, 2026 – 1:00 PM
Place: FENS L027
Keywords : MEMS, piezoresistive sensing, SOI, diaphragm, dynamic response
Abstract
This thesis presents a static and dynamic design methodology for an Silicon On Insulator (SOI) based piezoresistive Microelectromechanical Systems (MEMS) pressure sensor. Conventional sensor design focuses on static performance parameters such as sensitivity, linearity, and output voltage, while dynamic response is often evaluated after fabrication. However, in high speed Data Acqusition Systems (DAQ) pressure measurement applications, the sensor must reach its steady state response within the required time interval. To address this issue, the diaphragm geometry was first selected according to the response time requirement. An analytical formulation was developed by modeling the diaphragm as a second order system and using the first vibration mode of a clamped square plate. The analytical results were validated using COMSOL Multiphysics eigenfrequency and time dependent simulations. After satisfying the dynamic requirement, the static sensitivity was improved through piezoresistor placement and resistor geometry optimization. Trade off between sensitivity and response time has been clearly observed in this study. For the chosen diaphragm thickness of 22.8 μm, the obtained analytical and numerical results for first mode frequency were quite consistent with an error margin of 0.53%. With optimized resistor network, sensitivity was improved to 6.475 mV/V/psi. In addition, the design fabricated on an SOI based fabrication process. The front side fabrication was successfully completed, while backside membrane formation by potassium hydroxide (KOH) etching partially completed and it required further optimization
