Title :
A simple capacitance calculation formula for MEMS capacitive type sensors with square membranes
Author :
Rahman, Mosaddequr ; Abbas, Syed ; Chowdhury, Sazzadur
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Windsor, Windsor, ON, Canada
fDate :
June 28 2009-July 1 2009
Abstract :
A simple highly accurate mathematical method has been developed to calculate capacitance change for MEMS capacitive type sensors with square membranes. The method improves the accuracy of existing methods as it takes account of the membrane deflection due to the electrostatic pressure in addition to the external mechanical pressure, considers the fringing field effects, and is also applicable to large deflection cases. The model has been verified by 3-D electromechanical finite element analysis for a wide range of loading conditions. The model predicted values are found to be in excellent agreement with the FEA results with a maximum deviation of 5.08% for the membrane center deflection and 5.76% for capacitance values for different external pressure loading and electrostatic bias voltage.
Keywords :
capacitive sensors; electrostatic devices; finite element analysis; membranes; microsensors; 3D electromechanical finite element analysis; FEA; MEMS capacitive-type sensors; capacitance calculation formula; electrostatic bias voltage; electrostatic pressure; external mechanical pressure; external pressure loading; fringing field effects; membrane center deflection; square membranes; Acoustic sensors; Biomembranes; Capacitance; Capacitive sensors; Electrostatics; Mechanical sensors; Micromechanical devices; Residual stresses; Temperature sensors; Voltage;
Conference_Titel :
Circuits and Systems and TAISA Conference, 2009. NEWCAS-TAISA '09. Joint IEEE North-East Workshop on
Conference_Location :
Toulouse
Print_ISBN :
978-1-4244-4573-8
Electronic_ISBN :
978-1-4244-4574-5
DOI :
10.1109/NEWCAS.2009.5290456
