Floating-gate MOS transistors have been widely used in diverse analog and digital applications. One of these is as a charge sensitive device in sensors for pH measurement in solutions or using gates with metals like Pd or Pt for hydrogen sensing. Efforts are being made to monolithically integrate sensors together with controlling and signal processing electronics using standard technologies. This can be achieved with the demonstrated compatibility between available CMOS technology and MEMS technology. In this paper an in-depth analysis is done regarding the reliability of floating-gate MOS transistors when charge produced by a chemical reaction between metallic oxide thin films with either reducing or oxidizing gases is present. These chemical reactions need temperatures around 200 °C or higher to take place, so thermal insulation of the sensing area must be assured for appropriate operation of the electronics at room temperature. The operation principle of the proposal here presented is confirmed by connecting the gate of a conventional MOS transistor in series with a Fe₂O₃ layer. It is shown that an electrochemical potential is present on the ferrite layer when reacting with propane.

In this paper a modal analysis for a proposed capacitive MEMS accelerometer sensor that can be used as inclinometer, dynamic acceleration or vibration sensor, is shown. An analysis of the effect of frequency over the displacement of the movable electrode is made. Besides, it is shown that the natural frequencies and vibration modes depend on the application given to this capacitive sensor. Additionally, the structure here proposed can be manufactured using standard CMOS technology. This paper shows how the same capacitive structure can be used in a MEMS sensor no matter what type of application you will provide. A model of the accelerometer is presented. The simulations shown were obtained using COMSOL.

In this paper, a capacitance structure configured with two plates to be used as a MEMS-sensor is presented. This capacitor was designed primarily for being used in combination with a floating-gate MOS transistor (FGMOS) as the transducer device of an accelerometer. One of the plates of this capacitance structure is fixed and the other plate will move when a force is applied, causing a variable capacitance, this is achieved by a lateral comb configuration. This variable capacitance depends either on the mechanical properties of the material used in the structure, the undesired displacement caused by gravity and pull-in effect. Furthermore, the proposed design can be fabricated using standard CMOS technologies followed by a sacrificial layer etching needed for the structure release.

In this work, a design for a high G sensor is proposed demonstrating a novel transduction technique that can be fabricated with a standard 0.5μm CMOS technology. No additional modifications to the fabrication steps are needed to achieve a MEMS (Micro-Electro-Mechanical System) accelerometer. The proposed system uses Multiple Input Floating-gate MOS transistors (MIFGMOS) as capacitive transduction elements. A variable capacitance is configured between fingers attached to the proof mass as one plate, and to the fixed structure, as the other plate. When acceleration is applied, this results in a modification of the floating gate voltage of the FGMOS, with a corresponding current change that can be correlated to acceleration. Also, a mechanical study was made with a given geometry structure, as well as an electrical analysis of the FGMOS transistor performance. Finally, a layout is proposed for the accelerometer system. Therefore, it is demonstrated that this design can be fabricated with the desired specifications through a standard CMOS technology. Additionally a novel transduction alternative compared to that used in conventional designs is demonstrated.