Design of Electrostatic Micro Mirrors for Improved Stability Though Surface Contact

1998 ◽  
Author(s):  
Timothy Moulton ◽  
G. K. Ananthasuresh
Keyword(s):  
Design Method ◽  
Electrostatic Force ◽  
Electrostatic Actuation ◽  
Mems Devices ◽  
Complex Dynamic ◽  
Micro Electro Mechanical Systems ◽  
Electrostatically Actuated ◽  
Surface Contact ◽  
Improved Stability ◽  
Mems Process

Abstract There exists a need to stabilize the electrostatic actuation commonly used in Micro-Electro-Mechanical Systems (MEMS). Most electrostatically actuated MEMS devices act as variable capacitors with varying gap between the charged conductors. Electrostatic force in these devices is a nonlinear attractive force between the conductors resulting in a complex dynamic system. These systems are stable for only a small portion of the initial gap. In this paper a design method is presented for electrostatic micro-mirrors with improved stability. Controllable, stable electrostatic actuation can be achieved through surface contact between the two conductors. Once in contact with the surface, the compliance of the structure is used to stabilize the electrostatic actuation over a long range of motion. Beam based variable angle mirrors were designed and fabricated using the Multi-User MEMS Process at MCNC technology center. The design methods for stable electrostatic actuation were tested on these mirrors. Some characteristics are noted and their implementation into future designs is discussed.

scholarly journals Design of a large-range rotary microgripper with freeform geometries using a genetic algorithm

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Chen Wang ◽  
Yuan Wang ◽  
Weidong Fang ◽  
Xiaoxiao Song ◽  
Aojie Quan ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Human Hair ◽  
Design Methodology ◽  
Large Range ◽  
Design Method ◽  
Actuation Voltage ◽  
Superior Performance ◽  
Mems Devices ◽  
Electrostatically Actuated ◽  
Fabrication Tolerances

AbstractThis paper describes a novel electrostatically actuated microgripper with freeform geometries designed by a genetic algorithm. This new semiautomated design methodology is capable of designing near-optimal MEMS devices that are robust to fabrication tolerances. The use of freeform geometries designed by a genetic algorithm significantly improves the performance of the microgripper. An experiment shows that the designed microgripper has a large displacement (91.5 μm) with a low actuation voltage (47.5 V), which agrees well with the theory. The microgripper has a large actuation displacement and can handle micro-objects with a size from 10 to 100 μm. A grasping experiment on human hair with a diameter of 77 μm was performed to prove the functionality of the gripper. The result confirmed the superior performance of the new design methodology enabling freeform geometries. This design method can also be extended to the design of many other MEMS devices.

DYNAMICS OF ELECTROSTATICALLY ACTUATED MICRO-ELECTRO-MECHANICAL SYSTEMS: SINGLE DEVICE AND ARRAYS OF DEVICES

2009 ◽  
Vol 19 (03) ◽  
pp. 1007-1022 ◽  
Author(s):  
V. Y. TAFFOTI YOLONG ◽  
P. WOAFO
Keyword(s):  
Chaotic Behavior ◽  
Equilibrium Points ◽  
Dynamical Behavior ◽  
Mechanical Systems ◽  
Largest Lyapunov Exponent ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Electrostatically Actuated ◽  
In Series ◽  
Electrostatic Coupling

The dynamical behavior of micro-electro-mechanical systems (MEMS) with electrostatic coupling is studied. A nonlinear modal analysis approach is applied to decompose the partial differential equation into a set of ordinary differential equations. The stability analysis of the equilibrium points is investigated. The amplitudes of the harmonic oscillatory states in the triple resonant states are obtained and discussed. Chaotic behavior is investigated using bifurcations diagram and the largest Lyapunov exponent. The dynamics of the MEMS with multiple functions in series is also investigated as well as the transitions boundaries for the complete synchronization state in a shift-invariant set of coupled MEMS devices.

Micro/Nano Film Getters for Vacuum Maintenance of MEMS

2007 ◽  
Vol 353-358 ◽  
pp. 2924-2927
Author(s):  
Yu Feng Jin ◽  
Hao Tang ◽  
Zhen Feng Wang
Keyword(s):  
High Vacuum ◽  
External Environment ◽  
Mems Devices ◽  
Activation Temperature ◽  
Micro Electro Mechanical Systems ◽  
Mems Packaging ◽  
Basic Functions ◽  
Fabrication And Characterization ◽  
Mems Process

Vacuum packaging is very important for some micro-electro-mechanical systems (MEMS) devices to perform their basic functions properly and to enhance their reliability by keeping these devices away from harmful external environment. In order to maintain high vacuum in a cavity of MEMS devices, residual gases and leaking gases must be eliminated by embedded getter materials. Micro/Nano film getters absorbing gases inside the tiny cavity of MEMS packaging were introduced in this paper. The fabrication and characterization of micro/nano getters for MEMS applications were also presented. Various kinds of patterned getter films were prepared for different MEMS applications. The activation temperature and sorption capacity of the nonevaporable getter (NEG[1]) films was investigated. The formation of micro/nano films on the inner surface of MEMS devices is totally compatible with Si-based MEMS process and illustrates the applicability of the technique in vacuum maintenance of MEMS devices.

Reduced Order Model of MEMS Sensors Near Natural Frequency

2011 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Jose C. Solis Silva
Keyword(s):  
Natural Frequency ◽  
Nonlinear Response ◽  
Casimir Effect ◽  
Electrostatic Force ◽  
Reduced Order Model ◽  
Mass Detection ◽  
Order Model ◽  
Reduced Order ◽  
First Order ◽  
Electrostatically Actuated

The nonlinear response of an electrostatically actuated cantilever beam microresonator sensor for mass detection is investigated. The excitation is near the natural frequency. A first order fringe correction of the electrostatic force, viscous damping, and Casimir effect are included in the model. The dynamics of the resonator is investigated using the Reduced Order Model (ROM) method, based on Galerkin procedure. Steady-state motions are found. Numerical results for uniform microresonators with mass deposition and without are reported.

scholarly journals Micro-electro-mechanical systems (MEMS): Technology for the 21st century

2014 ◽  
Vol 68 (5) ◽  
pp. 629-641 ◽  
Author(s):  
Tatjana Djakov ◽  
Ivanka Popovic ◽  
Ljubinka Rajakovic
Keyword(s):  
21St Century ◽  
Low Cost ◽  
Mechanical Systems ◽  
Modern Society ◽  
Global Scale ◽  
Thermal Constant ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Industrial Sectors ◽  
Mems Technology

Micro-electro-mechanical systems (MEMS) are miniturized devices that can sense the environment, process and analyze information, and respond with a variety of mechanical and electrical actuators. MEMS consists of mechanical elements, sensors, actuators, electrical and electronics devices on a common silicon substrate. Micro-electro-mechanical systems are becoming a vital technology for modern society. Some of the advantages of MEMS devices are: very small size, very low power consumption, low cost, easy to integrate into systems or modify, small thermal constant, high resistance to vibration, shock and radiation, batch fabricated in large arrays, improved thermal expansion tolerance. MEMS technology is increasingly penetrating into our lives and improving quality of life, similar to what we experienced in the microelectronics revolution. Commercial opportunities for MEMS are rapidly growing in broad application areas, including biomedical, telecommunication, security, entertainment, aerospace, and more in both the consumer and industrial sectors on a global scale. As a breakthrough technology, MEMS is building synergy between previously unrelated fields such as biology and microelectronics. Many new MEMS and nanotechnology applications will emerge, expanding beyond that which is currently identified or known. MEMS are definitely technology for 21st century.

Effect of γ-ray irradiation on performance of LiNbO(3)-based piezoelectric vibration sensors

2021 ◽  
Author(s):  
Huifen Wei ◽  
Wenping Geng ◽  
Kaixi Bi ◽  
Tao Li ◽  
Xiangmeng Li ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Extreme Environments ◽  
Theoretical Work ◽  
High Dose ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Vibration Sensors ◽  
Irradiation Dosage ◽  
Gamma Ray Irradiation ◽  
Γ Ray

Abstract LiNbO3 (LN)-based micro-electro-mechanical systems (MEMS) vibration sensors exhibit giant prospection in extreme environments, where exist a great amount of irradiation. However, to the best of our knowledge, it is still unknown whether the irradiation affects the performance of LN-based piezoelectric MEMS sensors. Based on this consideration, it is necessary to model the irradiation environment to investigate the effect of high dosage irradiation on LN-based vibration sensors. Firstly, the theoretical work is done to study the Compton Effect on the Gamma-ray irradiation with Co-60 source. After irradiation, X-ray diffraction (XRD) characterization was performed to verify the effect of irradiation on the crystalline of LN thin film. Meanwhile, the performances of output voltages on the five MEMS devices under various dosage of irradiation are compared. As a result, a neglected shift of 0.02 degrees was observed from the XRD image only under maximum irradiation dosage of 100 Mrad(Si). Moreover, the output voltages of cantilever-beam vibration sensors decrease by 3.1%. Therefore, it is verified that the γ-ray irradiation has very little influence on the LN-based MEMS vibration sensors, which have great attraction on the materials and sensors under high-dose irradiation.

An Analytical Design Method for Milling Cutters With Non-Constant Pitch to Increase Stability

2000 ◽  
Author(s):  
Erhan Budak
Keyword(s):  
Surface Finish ◽  
Design Method ◽  
Stability Limit ◽  
Analytical Stability ◽  
Chatter Vibrations ◽  
Constant Pitch ◽  
Improved Stability ◽  
Limited Frequency ◽  
The Stability ◽  
Explicit Relation

Abstract Chatter vibrations result in reduced productivity, poor surface finish and decreased cutting tool life. Milling cutters with non-constant pitch angles can be very effective in improving the stability of the process against chatter. In this paper, an analytical stability model and a design method are presented for non-constant pitch cutters. An explicit relation is obtained between the stability limit and the pitch variation which leads to a simple equation for optimal pitch angles. A certain pitch variation is effective for limited frequency and speed ranges which are also predicted by the model. The improved stability, productivity and surface finish are demonstrated by several examples.

RF-MEMS Based Oscillators

2012 ◽  
pp. 120-155
Author(s):  
Anis Nurashikin Nordin
Keyword(s):  
Acoustic Wave ◽  
Rf Mems ◽  
Low Cost ◽  
Individual Characteristics ◽  
Bulk Acoustic Wave ◽  
Mems Devices ◽  
Device Structure ◽  
Micro Electro Mechanical Systems ◽  
Wireless Transceiver ◽  
Film Bulk

Today’s high-tech consumer market demand complex, portable personal wireless consumer devices that are low-cost and have small sizes. Creative methods of combining mature integrated circuit (IC) fabrication techniques with innovative radio-frequency micro-electro-mechanical systems (RF-MEMS) devices has given birth to wireless transceiver components, which operate at higher frequencies but are manufactured at the low-cost of standard ICs. Oscillators, RF bandpass filters, and low noise amplifiers are the most critical and important modules of any wireless transceiver. Their individual characteristics determine the overall performance of a transceiver. This chapter illustrates RF-oscillators that utilize MEMS devices such as resonators, varactors, and inductors for frequency generation. Emphasis will be given on state of the art RF-MEMS components such as film bulk acoustic wave, surface acoustic wave, flexural mode resonators, lateral and vertical varactors, and solenoid and planar inductors. The advantages and disadvantages of each device structure are described, with reference to the most recent work published in the field.

scholarly journals Microfluidic and Micromachined/MEMS Devices for Separation, Discrimination and Detection of Airborne Particles for Pollution Monitoring

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 483 ◽  
Author(s):  
Daniel Puiu Poenar
Keyword(s):  
Optical Scattering ◽  
Pollution Monitoring ◽  
Detection Methods ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Lab On Chip ◽  
Inorganic Particles ◽  
Advantages And Disadvantages ◽  
Air Quality Assessment ◽  
On Chip

Most of the microfluidics-related literature describes devices handling liquids, with only a small part dealing with gas-based applications, and a much smaller number of papers are devoted to the separation and/or detection of airborne inorganic particles. This review is dedicated to this rather less known field which has become increasingly important in the last years due to the growing attention devoted to pollution monitoring and air quality assessment. After a brief introduction summarizing the main particulate matter (PM) classes and the need for their study, the paper reviews miniaturized devices and/or systems for separation, detection and quantitative assessment of PM concentration in air with portable and easy-to-use platforms. The PM separation methods are described first, followed by the key detection methods, namely optical (scattering) and electrical. The most important miniaturized reported realizations are analyzed, with special attention given to microfluidic and micromachined or micro-electro-mechanical systems (MEMS) chip-based implementations due to their inherent capability of being integrated in lab-on-chip (LOC) type of smart microsystems with increased functionalities that can be portable and are easy to use. The operating principles and (when available) key performance parameters of such devices are presented and compared, also highlighting their advantages and disadvantages. Finally, the most relevant conclusions are discussed in the last section.

Dielectric Elastomer as a New Material for Electrostatically Actuated Microbeams: Stability Analysis

2019 ◽  
Vol 11 (10) ◽  
pp. 1950098
Author(s):  
Mohammad Fathalilou ◽  
Pegah Rezaei-Abajelou ◽  
Afsoon Vefaghi ◽  
Ghader Rezazadeh
Keyword(s):  
Pitchfork Bifurcation ◽  
Dielectric Elastomer ◽  
Micro Electro Mechanical Systems ◽  
High Deformation ◽  
Electrostatically Actuated ◽  
Eigen Value ◽  
Deformation Ability ◽  
New Material ◽  
The Stability ◽  
Stability Regime

Due to the interesting properties such as light weight and high deformation ability, dielectric elastomer (DE) resonators can be good alternatives for conventional silicon resonant beams used in micro-electro-mechanical systems (MEMS). This paper proposes a modeling in which a pre-stretched clamped-clamped DE-based microbeam oscillating above the ground substrate is subjected to an external electrostatic pressure. Using a DE-based beam affects the total rigidity of the system, which may lead to an anticipated saddle-node or pitchfork bifurcation. Hence, the present study tries to analyze the effects of DE properties on changing the stability regime of DE-based microbeams under electrostatic actuation. The stability of the system has been investigated using an eigen-value form of the problem. The effects of DE properties including pre-stress, relative permittivity and voltage value across the electrodes on pull-in or divergence instability as well as the frequency response of the system have been investigated. Moreover, the critical values of the DE voltage as a booster of instability occurrence have been obtained in either the presence or absence of the direct current (DC) voltage. It has been found that the pre-stress and appropriate DE permittivity can provide a needed magnitude of the DE actuating voltage to alter the resonance frequency and stability positions of the structure.

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