Bulk micromachined silicon comb-drive electrostatic actuators with diode isolation

Comb-drive electrostatic actuators have been widely applied to steer a gripper, an acceleratometer, a scanning mirror, and a xy-stage because their output forces are easily controlled and capacitively sensed. To obtain large displacement with low drive voltage, a comb-drive actuator has to be designed with narrower gap and larger overlapping area between two electrodes. As a result, it will induce the instability or side sticking during operation; that is, the stationary and the moving electrodes will stick together and the actuator fails to operate. Furthermore, due to the asymmetric electrodes caused by inevitably imperfect fabrication of the actuator, the comb-drive actuator may be unstable for a large displacement, resulting from the unbalanced electrostatic forces between two electrodes. We report a novel design, which utilizes a set of extra electrode structure to compensate the unbalanced electrostatic forces. Simulation results demonstrated that the larger displacement is achieved while the size of the comb-drive actuator keeps the same. For better performance, the design of electrode structure and the number of electrodes are discussed in this report.

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Demonstrating the Potential of a Novel Model to Improve Open-Loop Control of Electrostatic Comb-Drive Actuators in Electrolytes

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2017-71092 ◽

2017 ◽

Cited By ~ 1

Author(s):

Ohiremen Dibua ◽

Vikram Mukundan ◽

Beth Pruitt ◽

Ali Mani ◽

Gianluca Iaccarino

Keyword(s):

Open Loop ◽

Ion Concentration ◽

Native Oxide ◽

Open Loop Control ◽

Comb Drive ◽

Electrostatic Actuators ◽

Loop Control ◽

Biological Structures ◽

Potential Applications ◽

Novel Model

Electrostatic comb-drive actuators in electrolytes have many potential applications, including characterizing biological structures. Maximizing the utility of these devices for such applications requires a model capable of accurately predicting their behavior over both micron and submicron scales of displacement. Classic circuit models of these systems assume that the native oxide is a pure dielectric, and that the ion concentration of the bulk electrolyte is constant. We propose augmented models that separately address these assumptions, and analyze their ability to predict the displacement of the electrostatic actuators in electrolytic solutions. We find that the model which removes the assumption that the native oxide is a pure dielectric most accurately predicts comb-drive actuator behavior in electrolytes.

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Suppressing Residual Vibrations in Comb-drive Electrostatic Actuators: A Command Shaping Technique Adapted to Nomadic Applications

Sensors and Actuators A Physical ◽

10.1016/j.sna.2022.113366 ◽

2022 ◽

pp. 113366

Author(s):

Haythem Ameur ◽

Patrice Le Moal ◽

Gilles Bourbon ◽

Cedric Vuillemin ◽

Marc Sworowski

Keyword(s):

Comb Drive ◽

Electrostatic Actuators ◽

Command Shaping ◽

Shaping Technique

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Self‐sensing estimator for micromachined electrostatic actuators and parameters’ optimisation

Micro & Nano Letters ◽

10.1049/mnl.2016.0128 ◽

2016 ◽

Vol 11 (9) ◽

pp. 528-531 ◽

Cited By ~ 2

Author(s):

Chong Li ◽

Robert N. Dean ◽

George T. Flowers

Keyword(s):

Electrostatic Actuators

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An Equivalent Circuit Model for Vertical Comb Drive MEMS Optical Scanner Controlled by Pulse Width Modulation

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.132.1 ◽

2012 ◽

Vol 132 (1) ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Satoshi Maruyama ◽

Muneki Nakada ◽

Makoto Mita ◽

Takuya Takahashi ◽

Hiroyuki Fujita ◽

...

Keyword(s):

Equivalent Circuit ◽

Pulse Width ◽

Pulse Width Modulation ◽

Equivalent Circuit Model ◽

Circuit Model ◽

Comb Drive ◽

Optical Scanner

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Coulomb-actuated microbeams revisited: experimental and numerical modal decomposition of the saddle-node bifurcation

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00265-y ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Anton Melnikov ◽

Hermann A. G. Schenk ◽

Jorge M. Monsalve ◽

Franziska Wall ◽

Michael Stolz ◽

...

Keyword(s):

Finite Element ◽

Microelectromechanical Systems ◽

Dynamic Range ◽

Dynamic Performance ◽

Major Step ◽

Element Analysis ◽

Electrostatic Actuators ◽

Voltage Range ◽

Drive Voltage ◽

Depth Analysis

AbstractElectrostatic micromechanical actuators have numerous applications in science and technology. In many applications, they are operated in a narrow frequency range close to resonance and at a drive voltage of low variation. Recently, new applications, such as microelectromechanical systems (MEMS) microspeakers (µSpeakers), have emerged that require operation over a wide frequency and dynamic range. Simulating the dynamic performance under such circumstances is still highly cumbersome. State-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary information about unstable equilibrium states accordingly. Convincing lumped-parameter models amenable to direct physical interpretation are missing. This inhibits the indispensable in-depth analysis of the dynamic stability of such systems. In this paper, we take a major step towards mending the situation. By combining the finite element method (FEM) with an arc-length solver, we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams. A subsequent modal analysis then shows that within very narrow error margins, it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage range. An experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing precision. This enables modeling the system using a single spatial degree of freedom.

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