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Multiphysics interactions and non-linearity lead to a need of FEA softwares like Comsol, Coventors, Ansys,… • FEA softwares need powerful processors and a lot of time of computation • Reduced Order Models are a good alternative to accelerate the computations under some well chosen assumptions. • Energy flow modeling is a good way to implement such ROM, allowing to build a library of independent and acausal components that can be directly interfaced with electronic readout circuits. • MEMS Pressure Sensing • Energy Flow Modeling • Results

Since the emergence of the MEMS industry, rapid prototyping became crucial to allow for efficiently testing new designs at low cost by small batches production and rapid fabrication technologies as conductive polymer [1], conductive inkjet [2] or sacrificial-layer-free fabrication processes [3]. In the same time, flexible electronics is becoming one of the main emerging topics in the electronics field. In this work, we are experiencing a new ultra-fast-prototyping dry process that enables to produce functionalized capacitive membrane arrays on Kapton®, from Dupont®, polyimide as flexible substrate in an only oneday process philosophy based on laser etching. The process consists in releasing membranes by a calibrated laser etch in a Kapton, on the top of which a thin metal layer has been deposited, and next bonding the sheet on a metal-coated Pyralux® sheet, also from Dupont, that will act as bottom electrode and flexible substrate (fig. 1). In this work, the active 52µm Kapton sheet features 16 membranes of 1mm diameter and 25µm remaining polyimide thickness. Characterization of the etch speed is done considering three parameters as presented in [4]: laser velocity, V, number of etch passes, N, and the proportion of the total laser power, P, merged together as an etch factor that is N.P/V, the total laser power being 3.5W Multiple tests have been done showing good linearity following the ratio between the number of passes and speed (fig. 2). Multiple runs have been performed showing low variation in terms of etch depth (<5% of total depth), demonstrating the repeatability and predictability of the process. The roughness of the etched surface is another parameter of importance. Inhomogeneity in etch speed will directly lead to limitation in terms of minimum membrane thickness that can be reached with the laser etching. Measurements have been carried out with a topography measurement system showing roughness around 205nm (Ra) and 1.19µm (Rz) (Fig. 3). This will ensure

The pull-in time of electrostatically actuated parallel-plate microstructures enables the realization of a high-sensitivity accelerometer that uses time measurement as the transduction mechanism. The key feature is the existence of a metastable region that dominates pull-in behavior, thus making pull-in time very sensitive to external accelerations. Parallel-plate MEMS structures have been designed and fabricated using a SOI micromachining process (SOIMUMPS) for the implementation of the accelerometer. This paper presents the experimental characterization of the microdevices that validates the concept and the analytical models used. The accelerometer has a measured resolution of 0.25 ?s/?g and an estimated mechanical-thermal noise of View the MathML source2.8?g/Hz. Since the bandwidth of the sensor is directly related to the pull-in time (BW=2/tpi?180 Hz), the total measured noise floor of 400 ?g (110 ?s) suggests that the main noise source comes from the building vibrations, Microelectronics, Electrical Engineering, Mathematics and Computer Science

A high-resolution, high dynamic range capacitive accelerometer based on pull-in time measurement is described in this paper. The high sensitivity of pull-in time can be used to implement high performance accelerometers, but non-linearity and low dynamic range compromise device performance. A closed-loop approach using an electrostatic actuation mechanism to control the duration of the pull-in time is presented, which addresses the low dynamic range problem. Capacitive parallel-plates structures were used and the preliminary experimental results of closed-loop operation under several acceleration values confirm the potential of this technique and the overall accelerometer concept. The results show an accelerometer with high sensitivity (better than 6 ?V/?g) and improved linearity over a large dynamic range., Microelectronics, Electrical Engineering, Mathematics and Computer Science

The pull-in time of electrostatically actuated parallel-plate microstructures enables the realization of a high-sensitivity accelerometer that uses time measurement as the transduction mechanism. The key feature is the existence of a metastable region that dominates pull-in behavior, thus making pull-in time very sensitive to external accelerations. Parallel-plate MEMS structures have been designed and fabricated using a SOI micromachining process (SOIMUMPS) for the implementation of the accelerometer. This paper presents the experimental characterization of the microdevices that validates the concept and the analytical models used. The accelerometer has a measured resolution of 0.25 ?s/?g and an estimated mechanical-thermal noise of View the MathML source2.8?g/Hz. Since the bandwidth of the sensor is directly related to the pull-in time (BW=2/tpi?180 Hz), the total measured noise floor of 400 ?g (110 ?s) suggests that the main noise source comes from the building vibrations, Microelectronics, Electrical Engineering, Mathematics and Computer Science

A high-resolution, high dynamic range capacitive accelerometer based on pull-in time measurement is described in this paper. The high sensitivity of pull-in time can be used to implement high performance accelerometers, but non-linearity and low dynamic range compromise device performance. A closed-loop approach using an electrostatic actuation mechanism to control the duration of the pull-in time is presented, which addresses the low dynamic range problem. Capacitive parallel-plates structures were used and the preliminary experimental results of closed-loop operation under several acceleration values confirm the potential of this technique and the overall accelerometer concept. The results show an accelerometer with high sensitivity (better than 6 ?V/?g) and improved linearity over a large dynamic range., Microelectronics, Electrical Engineering, Mathematics and Computer Science

The experimental evaluation of damping-improved parallel-plate geometries is reported in this paper. An improved damper geometry with air channels was developed to address contradictory design constraints: large sensing parallel-plate area is desirable for a significant readout capacitance as well as reduced damping coefficient. Damping coefficients were measured at different gaps in conventional parallel-plates MEMS and in parallel-plates with air channels. The inertial masses of the fabricated structures were pulled-in and released. From the return to rest position trajectory, the damping coefficients, at each point, were extracted. Results show a significant damping decrease in parallel-plates with air channels without visible reduction in the capacitance value., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This work reports the design, modelling, fabrication and preliminary functionality testing of a dual-mass MEMS vibratory gyroscope for application in medical instrumentation, among others. The two-framed gyro has drive and sense mode resonance frequencies of 2500Hz and 2830Hz, with its bandwidth tunable between 40-330Hz. Adopted design and technological features such as the use of double-folded springs, quadrature-error-compensation electrodes and 50?m thick-SOI mechanical layer enable high resolution sensing. The designed sensor characteristics have been validated using FEM simulation and equivalent circuit modelling., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This paper describes an electro-mechanical auto-calibration technique for use in capacitive MEMS accelerometers. Auto-calibration is achieved using the combined information derived from an initial measurement of the resonance frequency and the measurement of the pull-in voltages during device operation, with an estimation of process-induced variations in device dimensions from layout and deviations in material properties from the known nominal value. An experiment-based analytical model is used to compute the required electrostatic forces required to simulate external accelerations allowing the electro-mechanical calibration of the accelerometer. Measurements on fabricated devices confirm the validity of the proposed technique and electro-mechanical calibration is experimentally demonstrated., Microelectronics, Electrical Engineering, Mathematics and Computer Science

The experimental evaluation of damping-improved parallel-plate geometries is reported in this paper. An improved damper geometry with air channels was developed to address contradictory design constraints: large sensing parallel-plate area is desirable for a significant readout capacitance as well as reduced damping coefficient. Damping coefficients were measured at different gaps in conventional parallel-plates MEMS and in parallel-plates with air channels. The inertial masses of the fabricated structures were pulled-in and released. From the return to rest position trajectory, the damping coefficients, at each point, were extracted. Results show a significant damping decrease in parallel-plates with air channels without visible reduction in the capacitance value., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This work reports the design, modelling, fabrication and preliminary functionality testing of a dual-mass MEMS vibratory gyroscope for application in medical instrumentation, among others. The two-framed gyro has drive and sense mode resonance frequencies of 2500Hz and 2830Hz, with its bandwidth tunable between 40-330Hz. Adopted design and technological features such as the use of double-folded springs, quadrature-error-compensation electrodes and 50?m thick-SOI mechanical layer enable high resolution sensing. The designed sensor characteristics have been validated using FEM simulation and equivalent circuit modelling., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This paper describes an electro-mechanical auto-calibration technique for use in capacitive MEMS accelerometers. Auto-calibration is achieved using the combined information derived from an initial measurement of the resonance frequency and the measurement of the pull-in voltages during device operation, with an estimation of process-induced variations in device dimensions from layout and deviations in material properties from the known nominal value. An experiment-based analytical model is used to compute the required electrostatic forces required to simulate external accelerations allowing the electro-mechanical calibration of the accelerometer. Measurements on fabricated devices confirm the validity of the proposed technique and electro-mechanical calibration is experimentally demonstrated., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This paper provides experimental validation of the predictions by two recent models for squeezed film damping in the free molecule regime. Measurements were carried out using a parallel-plate microstructure with a 2.29 ?m gap operated at pressures from 105 to 101 Pa (corresponding to Knudsen numbers from 0.03 to 300). Experiments are in good agreement with the modelling based on molecular dynamics at Knudsen numbers over 10. The result also indicates that modelling based on the modified Reynolds equation including inertia effects underestimates the damping due to end effects; however, it correctly predicts the trend for lower Knudsen numbers., Department of Microelectronics, Electrical Engineering, Mathematics and Computer Science

Squeeze-film damping is highly inadequate in low-pressure systems or in systems where air pressure and/or gap dimensions are poorly defined. Input shaping has been used to circumvent the oscillations typically associated with under-damped mass-spring-damper systems and drastically decrease the settling time. The proposed method does not rely on feedback but solely on the system dynamics. The required input signal is derived analytically from the differential equation describing the system. The resulting device response is simulated and experimentally verified on an electrostatically actuated microstructure. Settling occurs even faster than for an equivalent critically damped system., Microelectronics, Electrical Engineering, Mathematics and Computer Science

This paper provides experimental validation of the predictions by two recent models for squeezed film damping in the free molecule regime. Measurements were carried out using a parallel-plate microstructure with a 2.29 ?m gap operated at pressures from 105 to 101 Pa (corresponding to Knudsen numbers from 0.03 to 300). Experiments are in good agreement with the modelling based on molecular dynamics at Knudsen numbers over 10. The result also indicates that modelling based on the modified Reynolds equation including inertia effects underestimates the damping due to end effects; however, it correctly predicts the trend for lower Knudsen numbers., Department of Microelectronics, Electrical Engineering, Mathematics and Computer Science

Squeeze-film damping is highly inadequate in low-pressure systems or in systems where air pressure and/or gap dimensions are poorly defined. Input shaping has been used to circumvent the oscillations typically associated with under-damped mass-spring-damper systems and drastically decrease the settling time. The proposed method does not rely on feedback but solely on the system dynamics. The required input signal is derived analytically from the differential equation describing the system. The resulting device response is simulated and experimentally verified on an electrostatically actuated microstructure. Settling occurs even faster than for an equivalent critically damped system., Microelectronics, Electrical Engineering, Mathematics and Computer Science

A test technique for capacitive MEMS accelerometers and electrostatic microactuators, based on the measurement of pull-in voltages and resonance frequency, is described. Using this combination of measurements, one can estimate process-induced variations in the device layout dimensions as well as deviations from nominal value in material properties, which can be used either for testing or device diagnostics purposes. Measurements performed on fabricated devices confirm that the 250nm overetch observed on SEM images can be correctly estimated using the proposed technique., Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

A test technique for capacitive MEMS accelerometers and electrostatic microactuators, based on the measurement of pull-in voltages and resonance frequency, is described. Using this combination of measurements, one can estimate process-induced variations in the device layout dimensions as well as deviations from nominal value in material properties, which can be used either for testing or device diagnostics purposes. Measurements performed on fabricated devices confirm that the 250nm overetch observed on SEM images can be correctly estimated using the proposed technique., Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Microelectronics & Computer Engineering, Electrical Engineering, Mathematics and Computer Science

Microelectronics & Computer Engineering, Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science

Electrical Engineering, Mathematics and Computer Science