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MEMS technology has been applied in many fields including deep oil exploration and seismic detection areas, of which poor performance has limited its development until the sigma-delta modulation is added. Many of researches for improving the performance of MEMS acceleration sensor had been put forward. In this paper, an effective way for design of feed-forward sigma-delta for MEMS acceleration sensor is proposed. It is well know that simulation parameters are mainly about two parts including mechanical parameters and sigma-delta modulator parameters. Different mechanical parameters match the different sigma-delta parameters. Furthermore, the simulation model is designed successfully under idea environment in MATLAB, which cannot indicate it can reach the same performance in real environment through taped out. Therefore, the useful model parameters which had been verified by taped out can be the most valuable parameters for MEMS readout design. In this paper, the work shows an optimized parameters design with signal to noise ration (SNR) of 148 dB and its experimental result can reach 142 dB. [ABSTRACT FROM AUTHOR]

The performance of micro-machined sensors is primarily determined via the sensitivity of sensing electrode to displacement. This paper presents the design, modelling, optimization and fabrication of an active gap reduction mechanism used on a conventional comb drive to enhance the capacitance in a three axes capacitive micro accelerometer. The design parameters of the active gap reduced comb drive (AGRCD) are optimized for best performance. The finite element analysis of the AGRCD is performed for design verification. The modeling and simulation results demonstrated a 534 % increase in sensitivity of the three axes capacitive micro accelerometer. The three axes capacitive micro accelerometer with AGRCD is fabricated using a commercially available standard metal-multi user MEMS processes. [ABSTRACT FROM AUTHOR]

Package is one of the key technologies for MEMS accelerometers. This paper investigated the influence of package on performances of custom-designed MEMS piezoresistive accelerometer. Based on the designed package process, the effect of die adhesive and potting materials on the sensor sensitivity and residual stress were studied by theory analysis and experimental test. The results showed that: with more quantity of die adhesive when the thickness was fixed, the sensitivity of MEMS piezoresistive accelerometer was much smaller; in addition, with thicker die adhesive, the accelerometer had much bigger sensitivity and much smaller residual stress increment after the die attach process. Meanwhile, the sensitivity was proportional to the density of potting material, and it varied with the elastic modulus. [ABSTRACT FROM AUTHOR]

This paper presents a new micromachined z-axis accelerometer as well as a new method to sense the out-of-plane displacement capacitively via comb finger arrays. The new design built the z-accelerometer using eight folded beam suspension to minimize the off axis sensitivities in both the x- and y- directions. The proposed method implements the sensing electrode as a comb finger arrays surrounding the sensor. This method enables the realization of the sensor by bulk micromachining process, increases the sense capacitance and reduces the off-axis sensitivity. This process allows building the micromachined accelerometer with large inertial mass. This work introduces the design and simulation for this accelerometer. The introduced method results in a high sense capacitance as well as high sensitivity. The simulated sense capacitance is 19.6627 pF. The sensor sensitivity is 2.037 μm/g with a very small total noise equivalent acceleration of 3.096 μg/ $$ \sqrt {Hz} $$. [ABSTRACT FROM AUTHOR]

The present paper discusses a method for testing a MEMS capacitive accelerometer structure through electrical actuation. The response of a standard MEMS capacitive accelerometer structure for different electrical actuation voltages has been analyzed. The accelerometer structure along with a capacitance sensing integrated circuit (IC) MS3110 is modeled and simulated. A set of proto-type accelerometer structures is fabricated and packaged in PGA packages. The packaged MEMS structures and MS3110 IC are integrated on a printed circuit board. The MEMS structure is actuated by applying the electrical signal through the actuation fingers and the change in capacitance is measured by the MS3110 IC. The simulated and measured results show some interesting phenomenon like dipping and frequency doubling which are useful for initial testing and characterization of a MEMS accelerometer structure. [ABSTRACT FROM AUTHOR]

A new type of sensor to directly detect angular acceleration is essential for inertial and control technology. The above interest motivates us to propose a novel micro electromechanical system (MEMS) pendulum angular accelerometer with electrostatic actuator feedback. It adopts a proof pendulum with optimized moment of inertia, suspended to dual anchors by a pair of torsion spring beams, as sensing component. A pair of electrodes are designed as differential capacitors to detect the torsional angular of pendulum, then measure input angular acceleration in sensing axis. Another pair of electrodes are designed as electrostatic actuators for feedback control loop. The structure and operating principle of the MEMS angular accelerometer are introduced. Then, the structure kinetics analysis and signal detecting scheme based on differential capacitors are provided in detail, and the sensitivity and resolution of sensor are derived. Compared with the other MEMS angular accelerometers, the proof pendulum with optimized moment of inertia improves sensitivity and resolution of sensor. The electrostatic actuators feedback loop optimizes the dynamic capability and nonlinearity characteristic. The sensor is fabricated by MEMS fabrication technology. The ANSYS simulation and test results prove the validity of the theoretical analyses. The MEMS angular accelerometer can be used in industrial robots and aircraft by further implementing the signal processing electrocircuit. [ABSTRACT FROM AUTHOR]

This paper describes the design and characterization of an integrated sensor fabricated on the silicon on insulator wafer by micro electro mechanical systems technology. The integrated sensor is comprised of a tri-axis accelerometer, an absolute pressure sensor and a spreading-resistance temperature (SRT) sensor. The optimal size of the sensor structure, natural frequency and cross interference of these three sensors were simulated and determined by finite element analysis. The accelerometer with the cross structure has high sensitivity, good linearity and high response frequency proved by the static and dynamic experiments. The zero-drift, thermal zero-drift and thermal sensitivity of the accelerometer and absolute pressure sensor were also tested. The arrangement of SRT sensor with the wave structure was designed in detail. The optimal location of the SRT sensor was at the edge of chip to avoid stress interference. The integrated sensor with low cost, low mutual interference, smaller volume and good performance can be applied in mobile device, small military plane without driver and some other situations for environmental monitoring. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the editor discusses various articles within the issue on topics including sensors, Micro-Electro Mechanical System (MEMS) accelerometers, and in-vitro diagnostic device.