scholarly journals Characterization of capacitive MEMS resonators via nonlinear open-loop frequency responses

2015 ◽  
Author(s):  
A. Brenes ◽  
J. Juillard ◽  
L. Bourgois ◽  
F. Vinci dos Santos
Keyword(s):  
Open Loop ◽  
Frequency Responses ◽  
Mems Resonators ◽  
Capacitive Mems

scholarly journals A Tunable-Gain Transimpedance Amplifier for CMOS-MEMS Resonators Characterization

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Rafel Perelló-Roig ◽  
Jaume Verd ◽  
Sebastià Bota ◽  
Jaume Segura
Keyword(s):  
Cmos Technology ◽  
Open Loop ◽  
Transimpedance Amplifier ◽  
Mems Devices ◽  
Monolithically Integrated ◽  
Mems Resonators ◽  
Electromechanical Performance ◽  
Cmos Mems ◽  
Promising Solution ◽  
On Chip

CMOS-MEMS resonators have become a promising solution thanks to their miniaturization and on-chip integration capabilities. However, using a CMOS technology to fabricate microelectromechanical system (MEMS) devices limits the electromechanical performance otherwise achieved by specific technologies, requiring a challenging readout circuitry. This paper presents a transimpedance amplifier (TIA) fabricated using a commercial 0.35-µm CMOS technology specifically oriented to drive and sense monolithically integrated CMOS-MEMS resonators up to 50 MHz with a tunable transimpedance gain ranging from 112 dB to 121 dB. The output voltage noise is as low as 225 nV/Hz1/2—input-referred current noise of 192 fA/Hz1/2—at 10 MHz, and the power consumption is kept below 1-mW. In addition, the TIA amplifier exhibits an open-loop gain independent of the parasitic input capacitance—mostly associated with the MEMS layout—representing an advantage in MEMS testing compared to other alternatives such as Pierce oscillator schemes. The work presented includes the characterization of three types of MEMS resonators that have been fabricated and experimentally characterized both in open-loop and self-sustained configurations using the integrated TIA amplifier. The experimental characterization includes an accurate extraction of the electromechanical parameters for the three fabricated structures that enables an accurate MEMS-CMOS circuitry co-design.

Design and characterization of a hybrid soft gripper with active palm pose control

2020 ◽  
Vol 39 (14) ◽  
pp. 1668-1685 ◽  
Author(s):  
Vignesh Subramaniam ◽  
Snehal Jain ◽  
Jai Agarwal ◽  
Pablo Valdivia y Alvarado
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structure ◽  
Element Model ◽  
Open Loop ◽  
Aspect Ratios ◽  
Maximum Payload ◽  
Wide Range ◽  
Pose Control

The design and characterization of a soft gripper with an active palm to control grasp postures is presented herein. The gripper structure is a hybrid of soft and stiff components to facilitate integration with traditional arm manipulators. Three fingers and a palm constitute the gripper, all of which are vacuum actuated. Internal wedges are used to tailor the deformation of a soft outer reinforced skin as vacuum collapses the composite structure. A computational finite-element model is proposed to predict finger kinematics. Thanks to its active palm, the gripper is capable of grasping a wide range of part geometries and compliances while achieving a maximum payload of 30 N. The gripper natural softness enables robust open-loop grasping even when components are not properly aligned. Furthermore, the grasp pose of objects with various aspect ratios and compliances can be robustly maintained during manipulation at linear accelerations of up to 15 m/s2 and angular accelerations of up to 5.23 rad/s2.

New control methodology for a morphing wing demonstrator

2017 ◽  
Vol 232 (8) ◽  
pp. 1479-1494 ◽  
Author(s):  
Michel Joël Tchatchueng Kammegne ◽  
Yvan Tondji ◽  
Ruxandra Mihaela Botez ◽  
Lucian Teodor Grigorie ◽  
Mahmoud Mamou ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Open Loop ◽  
Post Processing ◽  
Pressure Data ◽  
Morphing Wing ◽  
Subsonic Wind Tunnel ◽  
Logic Control ◽  
Flexible Part ◽  
Control Methodology

A morphing wing can improve the aircraft aerodynamic performance by changing the wing airfoil depending on the flight conditions. In this paper, a new control methodology is presented for a morphing wing demonstrator tested in a subsonic wind tunnel in the open-loop configuration. Actuators integrated inside the wing are used to modify the flexible structure, which is an integral part of the wing. In this project, the actuators are made in-house and controlled with logic control, which is developed within the main frame of this work. The characterization of the flow (laminar or turbulent) over the wing is obtained starting from the pressure signals measured over the flexible part of the wing (upper surface). The signals are acquired by using some pressure sensors (Kulite sensors) incorporated in this flexible part of the wing upper surface. The technique used to collect Kulite pressure data and the post-processing methodology are explained. The recorded pressure data are sometimes subjected to noise, which is filtered before being processed. The standard deviation and power spectrum visualization of the pressure data approaches are used to evaluate the quality of the flow over the wing and estimate the transition point position in the area monitored by the Kulite sensors. In addition, infrared thermography visualization is implemented to observe the transition region over the entire wing upper surface, and to validate the methodology applied to the pressure data in this way. The demonstrator measures 1.5 m chordwise and 1.5 m spanwise. Four miniature actuators fixed on two actuation lines are used to morph the wing. The wing is also equipped with a rigid aileron. The experimental aerodynamic results obtained after post processing validate the numerical prediction for the transition location.

scholarly journals Advanced thermo-mechanical characterization of organic materials by piezoresistive organic resonators

2015 ◽  
Vol 2 (1) ◽  
pp. 106-112 ◽  
Author(s):  
D. Thuau ◽  
C. Ayela ◽  
E. Lemaire ◽  
S. Heinrich ◽  
P. Poulin ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Organic Materials ◽  
Mechanical Characterization ◽  
Low Cost ◽  
Mems Resonators

Rapid, low-cost and accurate characterization of the viscoelastic properties of organic materials using piezoresistive MEMS resonators.

Synthetic Esters and Dynamics of Pressure Compensated Proportional Directional Control Valves

2018 ◽  
Author(s):  
J. H. Jakobsen ◽  
M. R. Hansen
Keyword(s):  
Closed Loop ◽  
Closed Loop Control ◽  
Third Order ◽  
Loop Control ◽  
Synthetic Ester ◽  
Frequency Responses ◽  
Directional Control ◽  
Test Parameters ◽  
The Difference

The purpose of this paper is to help reduce the uncertainty in behavior introduced when changing hydraulic oil from mineral oil (HLP) to biodegradable oil (synthetic esters - HEES) by comparing the behavior of proportional valves with HLP and with HEES at various temperatures. The focus of this article is on classic proportional valves used in the industry. The study is based on tests and modelling with characterization of dynamic behavior in mind. The characterization is based on tests of two pressure compensated proportional valves, one with closed loop control of the spool position, and one without. The two ester types tested are one based on a saturated, fully synthetic ester and a regular fully synthetic ester. The tests consist of steps and frequency responses. Both valves are tested at oil temperatures 20°C, 40°C and 60°C. The adopted models are based on a third order linear model with parameters identified using frequency responses from actual valve tests. The variation of amplitude and bias has some influence on the resulting frequency response especially at lower temperatures. But the general tendencies are unaffected by amplitude and bias. As expected a clear tendency for both valves of increasing dampening at decreasing temperatures is seen regardless of oil type, but the increase in dampening is similar for all oil types. The saturated ester leads to less bandwidth at lower temperatures for both valves, but the overall variations between all oil types stay within 1.66Hz of each other when tested with the same test parameters. The investigation indicates that the difference in dynamic characteristics at 20°C caused by the different oil types can not be explained with variations in any single one of the classic liquid properties density and viscosity and more investigations are needed to identify the cause.

New Microstrip Diplexer for Recent Wireless Applications

2018 ◽  
Vol 7 (3.4) ◽  
pp. 96 ◽  
Author(s):  
Yaqeen S. Mezaal ◽  
Seham A. Hashim ◽  
Aqeel H.Al-fatlawi ◽  
Hussein A. Hussein
Keyword(s):  
Insertion Loss ◽  
Return Loss ◽  
Design Method ◽  
Open Loop ◽  
Coupled Resonators ◽  
Wireless Applications ◽  
Frequency Responses ◽  
Operating Band ◽  
Dual Channel ◽  
Better Than

In this study, dual-channel diplexer using microstrip open loop coupled resonators has been designed and simulated; each channel has two operating band frequencies. This microstrip diplexer is designed for (1.424/1.732GHz) for first channel and (2.014/2.318GHz) for second channel. The simulated results for this device have insertion loss (1.8 and 1 dB) at load 1, and (1.5 and 3 dB) at load 2. Additionally, it has reasonable return loss magnitudes better than 10 dB and effective isolation between channels of35 dB. The proposed design has shown an uncomplicated topology, an effectual design method, small circuit size and narrowband frequency responses that are fitting for multi service wireless schemes.  

scholarly journals Piezoelectric MEMS Resonators for Cigarette Particle Detection

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
Javier Toledo ◽  
Víctor Ruiz-Díez ◽  
Maik Bertke ◽  
Hutomo Suryo Wasisto ◽  
Erwin Peiner ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Closed Loop ◽  
Low Cost ◽  
Open Loop ◽  
Piezoelectric Resonator ◽  
Particle Detection ◽  
Interface Circuit ◽  
Mems Resonators ◽  
Loading Effects ◽  
Working Principle

In this work, we demonstrate the potential of a piezoelectric resonator for developing a low-cost sensor system to detect microscopic particles in real-time, which can be present in a wide variety of environments and workplaces. The sensor working principle is based on the resonance frequency shift caused by particles collected on the resonator surface. To test the sensor sensitivity obtained from mass-loading effects, an Aluminum Nitride-based piezoelectric resonator was exposed to cigarette particles in a sealed chamber. In order to determine the resonance parameters of interest, an interface circuit was implemented and included within both open-loop and closed-loop schemes for comparison. The system was capable of tracking the resonance frequency with a mass sensitivity of 8.8 Hz/ng. Although the tests shown here were proven by collecting particles from a cigarette, the results obtained in this application may have interest and can be extended towards other applications, such as monitoring of nanoparticles in a workplace environment.

Sign in / Sign up

Export Citation Format

Share Document