This paper is focused on a novel design of stepped diaphragm for MEMS capacitive pressure sensor used in tire pressure monitoring system. The structure of sensor diaphragm plays a key role for determining the sensitivity of the sensor and the non-linearity of the output.First the structures of two capacitive pressure sensors with clamped square flatdiaphragms, with different thicknesses are inv...

In this paper modeling of capacitance and sensitivity for MEMS capacitive pressure sensor is presented. In capacitive sensor the sensitivity is proportional to deflection and capacitance changes versus pressure. Therefore first the diaphragm displacement, capacitance and sensitivity of sensor with square diaphragm have been modeled and then simulated using finite element method (FEM).  It can b...

In this paper excitation characteristics of the Liquid Crystal (LC) capacitive chemical and biological sensor are examined and the optimum frequency and voltage range for the sensor interface are introduced. Interdigitated capacitor has been used for the sensor capacitance measurement and two different molecular orientations, homeotropic and homogenous, have been considered. The LC sensor capac...

In this paper a new design of MEMS capacitive fingerprint sensors is presented. The capacitive sensor is made of two parallel plates with air gap. In these sensors, the capacitance changes is very important factor. It is caused by deformation of the upper electrode of sensor. In this study with making slots in upper electrode, using T-shaped protrusion on diaphragm in order to concentrate the f...

Low noise position measurement is fundamental for space inertial sensors, and at present the capacitive position sensor is widely employed for space inertial sensors. The design for the possible suppression of the front-end electric noises for a capacitive sensor is presented. A prototype capacitive sensor with 2×10−6pF/Hz1/2 at frequency above 0.04 Hz is achieved and further improvements are d...

This paper presents the design, construction and testing of a new capacitive tactile sensor for measurement of normal tactile force. The operation of proposed sensor has been investigated in ASTABLE and MONOSTABLE circuits. According to the results of these circuits the deviation of ASTABLE circuit results is less than MONOSTABLE circuit results. In addition, the results obtained from ASTABLE c...

This paper proposes a Micro-electro-mechanical (MEMS) capacitive pressure sensor that relies on the movable electrode displaced like a flat plate equal to the maximum center deflection of diaphragm. The diaphragm, movable electrode and mechanical coupling are made of polysilicon, gold and Si3N4, respectively. The fixed electrode is gold and the substrate is Pyrex glass. This proposed method inc...

Abstract   In this paper analytical analysis of capacitive pressure sensor with clamped diaphragm is presented. Mechanical and electrical properties of the sensor are theoretically analyzed based on theory of thin plates with small deflection and the results are evaluated by use of finite element analysis. The central deflection and capacitance values under uniform external pressure are calcula...