A New Design of Large Stroke Micro-Deformable Mirror Actuated by Electrostatic Repulsive Force

2008 ◽  
Author(s):  
Fangrong Hu ◽  
Jun Yao ◽  
Chuankai Qiu ◽  
Dajia Wang
Keyword(s):  
Electric Field ◽  
Resonant Frequency ◽  
Adaptive Optics ◽  
Bottom Electrode ◽  
Sacrificial Layer ◽  
Electrostatic Force ◽  
Repulsive Force ◽  
Deformable Mirror ◽  
Optical Aberrations ◽  
Out Of Plane

In this paper, a MEMS mirror actuated by an electrostatic repulsive force has been proposed and analyzed. The mirror consists of four U-shape springs, a fixed bottom electrode and a movable top electrode, there are many comb fingers on the edges of both electrodes. When the voltage is applied to the top and bottom electrodes, an asymmetric electric field is generated to the top movable fingers and springs, thus a net electrostatic force is produced to move the top plate out of plane. This designed micro-mirror is different from conventional MDM based on electrostatic-attractive-force, which is restricted by one-third thickness of the sacrificial layer for the pull-in phenomenon. The characteristic of this MDM has been analyzed, the result shows that the resonant frequency of the first mode is 8 kHz, and the stroke reaches 10μm at 200V, a MDM with large strokes can be realized for the application of adaptive optics in optical aberrations correction.

scholarly journals A Novel Capacitive Sensing Principle for Microdevices

2015 ◽  
Author(s):  
Jian Zhou ◽  
Ronald N. Miles ◽  
Shahrzad Towfighian
Keyword(s):  
Electric Field ◽  
Driving Force ◽  
Design Principle ◽  
Electrostatic Force ◽  
Low Cost ◽  
Repulsive Force ◽  
Attractive Force ◽  
Sensor Design ◽  
Capacitive Sensing

Conventional capacitive sensing places significant limitations on the sensor design due to the pull-in instability caused by the electrostatic force. The main purpose of this study is to examine a low-cost novel capacitive sensing principle based on electrostatic balance which promises to avoid these design limitations. The approach uses an asymmetric electric field on a structure with fingers that can generate a repulsive force while the gap is low and create an attractive force while the gap is large. The size and thickness of the fingers are also responsible for creating repulsive or attractive forces on the structure. This approach has recently been applied successfully in the design of capacitive actuators to provide a repulsive driving force. A new design principle for capacitive sensing is described that avoids pull-in instability by designing the fingers such that the structure is at the equilibrium.

scholarly journals Dual-view light-sheet imaging through tilted glass interface using a deformable mirror

2020 ◽  
Author(s):  
N Vladimirov ◽  
F Preusser ◽  
J Wisniewski ◽  
Z Yaniv ◽  
RA Desai ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
High Speed ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Light Sheet ◽  
Stochastic Gradient Descent ◽  
Deformable Mirror ◽  
Optical Aberrations ◽  
Light Sheet Microscopy ◽  
Gradient Descent Algorithm

AbstractLight-sheet microscopy has become one of the primary tools for imaging live developing organisms because of its high speed, low phototoxicity, and optical sectioning capabilities. Detection from multiple sides (multi-view imaging) additionally allows nearly isotropic resolution via computational merging of the views. However, conventional light-sheet microscopes require that the sample is suspended in a gel to allow optical access from two or more sides. At the same time, the use of microfluidic devices is highly desirable for many experiments, but geometric constrains and strong optical aberrations caused by the coverslip titled relative to objectives make the use of multi-view lightsheet challenging for microfluidics.In this paper we describe the use of adaptive optics (AO) to enable multi-view light-sheet microscopy in such microfluidic setup by correcting optical aberrations introduced by the tilted coverslip. The optimal shape of deformable mirror is computed by an iterative stochastic gradient-descent algorithm that optimizes PSF in two orthogonal planes simultaneously. Simultaneous AO correction in two optical arms is achieved via a knife-edge mirror that splits excitation path and combines the detection path.We characterize the performance of this novel microscope setup and, by dual-view light-sheet imaging of C.elegans inside a microfluidic channel, demonstrate a drastic improvement of image quality due to AO and dual-view reconstruction. Our microscope design allows multi-view light-sheet microscopy with microfluidic devices for precisely controlled experimental conditions and high-content screening.

scholarly journals Reinterpretation of Electric Field with Quantum Fluctuations: The Mechanism of Electrostatic Force of Attraction and Repulsion Between Two Point Charges

2020 ◽  
pp. 28-33
Author(s):  
C. G. Sim
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Vacuum Polarization ◽  
Quantum Fluctuation ◽  
Casimir Effect ◽  
Electrostatic Force ◽  
Quantum Fluctuations ◽  
Repulsive Force ◽  
Fluctuation Energy ◽  
Virtual Pairs

Vacuum polarization rearranges virtual  pairs. This causes the virtual  pairs to rigidify in vacuum, reducing the quantum fluctuation energy. The quantum fluctuation energy is a fundamental force of vacuum, as evidenced by the Casimir effect. The change in quantum fluctuation energy was simulated in the superposition of the electric fields. The results show that the increase and decrease of the quantum fluctuation energy between the two point charges is related to the repulsive force and attraction in Coulomb's law.

scholarly journals A MEMS Fabrication Process with Thermal-Oxide Releasing Barriers and Polysilicon Sacrificial Layers for AlN Lamb-Wave Resonators to Achieve fs·Qm > 3.42 × 1012

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 892
Author(s):  
Jicong Zhao ◽  
Zheng Zhu ◽  
Haiyan Sun ◽  
Shitao Lv ◽  
Xingyu Wang ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Lamb Wave ◽  
Piezoelectric Layer ◽  
Sacrificial Layer ◽  
High Quality ◽  
Micro Electro Mechanical Systems ◽  
Mems Fabrication ◽  
Thermal Oxide ◽  
Series Resonant ◽  
Releasing Process

This paper presents a micro-electro-mechanical systems (MEMS) processing technology for Aluminum Nitride (AlN) Lamb-wave resonators (LWRs). Two LWRs with different frequencies of 402.1 MHz and 2.097 GHz by varying the top interdigitated (IDT) periods were designed and fabricated. To avoid the shortcomings of the uncontrollable etching of inactive areas during the releasing process and to improve the fabrication yield, a thermal oxide layer was employed below the platted polysilicon sacrificial layer, which could define the miniaturized release cavities well. In addition, the bottom Mo electrode that was manufactured had a gentle inclination angle, which could contribute to the growth of the high-quality AlN piezoelectric layer above the Mo layer and effectively prevent the device from breaking. The measured results show that the IDT-floating resonators with 12 μm and 2 μm electrode periods exhibit a motional quality factor (Qm) as high as 4382 and 1633. The series resonant frequency (fs)·Qm values can reach as high as 1.76 × 1012 and 3.42 × 1012, respectively. Furthermore, Al is more suitable as the top IDT material of the AlN LWRs than Au, and can contribute to achieving an excellent electrical performances due to the smaller density, smaller thermo-elastic damping (TED), and larger acoustic impedance difference between Al and AlN.

scholarly journals Layer- and gate-tunable spin-orbit coupling in a high-mobility few-layer semiconductor

2021 ◽  
Vol 7 (5) ◽  
pp. eabe2892
Author(s):  
Dmitry Shcherbakov ◽  
Petr Stepanov ◽  
Shahriar Memaran ◽  
Yaxian Wang ◽  
Yan Xin ◽  
...  
Keyword(s):  
Electric Field ◽  
High Mobility ◽  
Orbit Coupling ◽  
Spin Splitting ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Quantum Oscillations ◽  
Out Of Plane ◽  
Order Of Magnitude ◽  
Spin Degeneracy

Spin-orbit coupling (SOC) is a relativistic effect, where an electron moving in an electric field experiences an effective magnetic field in its rest frame. In crystals without inversion symmetry, it lifts the spin degeneracy and leads to many magnetic, spintronic, and topological phenomena and applications. In bulk materials, SOC strength is a constant. Here, we demonstrate SOC and intrinsic spin splitting in atomically thin InSe, which can be modified over a broad range. From quantum oscillations, we establish that the SOC parameter α is thickness dependent; it can be continuously modulated by an out-of-plane electric field, achieving intrinsic spin splitting tunable between 0 and 20 meV. Unexpectedly, α could be enhanced by an order of magnitude in some devices, suggesting that SOC can be further manipulated. Our work highlights the extraordinary tunability of SOC in 2D materials, which can be harnessed for in operando spintronic and topological devices and applications.

Soft X-ray emission from an anharmonic collisional nanoplasma by a laser–nanocluster interaction

2021 ◽  
Vol 87 (3) ◽  
Author(s):  
R. Nemati Siahmazgi ◽  
S. Jafari
Keyword(s):  
Electric Field ◽  
Laser Beam ◽  
Resonant Frequency ◽  
Restoring Force ◽  
Cluster Radius ◽  
X Ray ◽  
Nonlinear Restoring Force ◽  
Cluster Temperature ◽  
Argon Clusters ◽  
Helium Neon

The purpose of the present paper is to investigate the generation of soft X-ray emission from an anharmonic collisional nanoplasma by a laser–nanocluster interaction. The electric field of the laser beam interacts with the nanocluster and leads to ionization of the cluster atoms, which then produces a nanoplasma. Because of the nonlinear restoring force in an anharmonic nanoplasma, the fluctuations and heating rate of, as well as the power radiated by, the electrons in the nanocluster plasma will be notably different from those arising from a linear restoring force. By comparing the nonlinear restoring force state (which arises from an anharmonic cluster) with that of the linear restoring force (in harmonic clusters), the cluster temperature specifically changes at the resonant frequency relative to the linear restoring force, while the variation of the anharmonic cluster radius is almost identical to that of the harmonic cluster radius. In addition, it is revealed that a sharp peak of X-ray emission arises after some picoseconds in deuterium, helium, neon and argon clusters.

Electrostatic Forces on Particles Floating Within the Interface Between Two Immiscible Fluids

2007 ◽  
Author(s):  
Nadine Aubry ◽  
Pushpendra Singh
Keyword(s):  
Dielectric Properties ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
External Electric Field ◽  
Capillary Force ◽  
Electrostatic Force ◽  
Immiscible Fluids ◽  
Electrostatic Forces ◽  
Dipole Interactions

The objective of this paper is to study the dependence of the electrostatic force that act on a particle within the interface between two immiscible fluids on the parameters such as the dielectric properties of the fluids and particles, the particle’s position within the interface, and the electric field strength. It is shown that the component of electrostatic force normal to the interface varies as a2, where a is the particle radius, and since in equilibrium it is balanced by the vertical capillary force, the interfacial deformation caused by the particle changes when an external electric field is applied. In addition, there are lateral electrostatic forces among the particles due to the dipole-dipole interactions which, when the distance between two particles is O(a), vary as a2, and remain significant for submicron sized particles.

A Frequency-Tunable Comb Resonator Using Spring Tension and Compression Effects

2004 ◽  
Author(s):  
Ki Bang Lee ◽  
Albert P. Pisano ◽  
Liwei Lin
Keyword(s):  
Resonant Frequency ◽  
Bias Voltage ◽  
Frequency Tuning ◽  
Electrostatic Force ◽  
Voltage Change ◽  
Tension And Compression ◽  
Frequency Tunable ◽  
Frequency Changes ◽  
Compression Effects ◽  
First Time

A 2μm-thick frequency-tunable microresoantor capable of either increasing or decreasing its resonant frequency by a combination of Joule heating and electrostatic force has been successfully demonstrated for the first time. For the heating voltage increase from 0 to 2V under fixed bias voltage of 40V, the resonant frequency changes from 22.2kHz to 16.2kHz, resulting in the 27% reduction in the resonant frequency. For the bias voltage change from 20V to 40V under the heating voltage of 0V, the resonant frequency increase from 19.0kHz to 23.6kHz, resulting in the 24.2% increase in the resonant frequency. As such, this surface-micromachined microactuator could assist complicated frequency tuning for applications of microsensors and microactuators.

Sign in / Sign up

Export Citation Format

Share Document