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This paper investigates the way of adding lumped masses on decaying time constant of the disk resonator gyroscope (DRG). Three typical ways of adding lumped masses are discussed and compared in detail. The longest decay time constant of 9.357 s is presented. In addition, this paper also demonstrates that adding lumped masses has the capability of reducing the bias and bias drift of the DRG. The figure...
An advanced micromachining process has been developed to further enhance the performance and to reduce the size of mass-produced inertial MEMS. In this new platform technology two independent silicon layers instead of one can be used to form more complex 3D-like masses, springs, and free-standing electrodes. The first accelerometer generations for automotive and CE applications are already in series...
A MEMS scanning mirror based on a deformable SU-8 membrane mirror supported by a biaxial gimbal with SU-8 flexures delivers 3-dimensional beam scanning for a handheld confocal microscope. Beam scanning and focusing performance are characterized.
We present the design of an analog Silicon Photonic MEMS phase shifter based on vertically moving adiabatic couplers. Using a two-step electrostatic actuation method, the phase shifter can be turned on selectively by applying an actuation voltage on a first pair of electrodes, and the phase of the optical signal can be tuned continuously by applying an actuation voltage at a second electrode pair...
We present a unique lateral bulk resonance mode with a lateral strain profile that resembles a shirt button that we transduce piezoelectrically in a MEMS disk resonator. This button-like (BL) mode offers the 3-fold benefits of (1) intrinsic feedthrough cancellation using fully-differential transduction, (2) strong piezoelectric coupling from the associated strain profile, and (3) higher quality (Q)...
We present a novel MEMS capacitance accelerometer with single wafer symmetrical double-sided folded-beams structure. The highly symmetrical 8 folded-beams on single wafer is designed and fabricated by Deep Reactive Ion Etch (DRIE) and KOH wet etching from both sides of the silicon wafer. The sandwich differential capacitive accelerometer is formed by three-layer silicon-silicon bonding. The excellent...
We present a fabrication method for thin-film polymer MEMS that achieves an order of magnitude improvement in feature size and resolution. Specifically, we modified the electron beam lithography (EBL) process for biocompatible poly(chloro-para-xylylene) (Parylene C), enabling flexible, encapsulated titanium structures with features as small as 100 nm. The mechanical, electrical and material properties...
An advanced micromachining process has been developed to further push the performance limits of mass-produced inertial MEMS. The main achievement of the new platform technology is the usage of two independent silicon layers instead of one to form, e.g., masses, springs, and free-standing electrodes. This dual layer process option opens the path towards new 3D-like sensor topologies with improved performance...
This study based on piezo-electric sensing principle to develop a high S/N ratio MEMS microphone. The patterned PZT and electrodes designed implemented above the clamped diaphragm to generate high stress concentration on PZT and Si bimorph diaphragm. The proposed central-circle electrode design can induce more charge than the edge-surrounded electrode design (served as the reference design). The proposed...
This paper presents, what is to the authors' knowledge, the smallest MEMS gyroscope reported to date. With a footprint of only 0.5 mm2, the device consists of a high frequency bulk acoustic wave (BAW) disk resonator (408 um diameter) with robust performance to environmental disturbances, and a large dynamic range of more than 6,000 °/s. The device utilizes nano-transduction capacitive gaps provided...
We investigated the effect of short beam length and gap distance between short beams on the resonance frequencies in Fishbone-shaped MEMS resonator. To do so, we fabricated three different kinds of Fishbone-shaped MEMS resonators, and measured their resonance frequencies. Moreover, we investigated the resonance frequencies by the simulation, which were compared with measurement results and they were...
A systematical study is performed to analyze the spurious modes, Q and electromechanical coupling of 1.22 GHz AlN MEMS contour-mode resonators. A total of 135 different geometrical configurations were studied. An unloaded Q of up to 3157, an electromechanical coupling of up to 2.3%, and a figure of merit of up to 61.6 were achieved. In particular, we found that Q is primarily affected by finger length...
High frequency wine-glass mode bulk MEMS resonators actuated by means of capacitive transduction have been fabricated by using solid-gaps based on polyvinylidenefluoride-trifluoroethylene (PVDF-TrFE). The fabrication process flow of patterned PVDF-TrFE gaps applied in RF MEMS is presented for the first time. Measurements of the polarization of the material and the frequency and voltage dependence...
A micromachined silicon hemispherical resonator with self-aligned silicon spherical capacitive electrodes is developed for the first time. Spherical electrodes, owning the same curvature of the resonator shell, surround the shell and extend into the cave deeply (160μm). The gap between the electrodes and shell is made by a sacrificial layer and a uniform and small (1.5μm) gap is obtained, which enables...
This paper presents a MEMS-based capacitive pressure sensor with pre-stressed sensing diaphragms for achieving a linear response with applied pressure. The sensor is designed to work in touch-mode by using sensing pressure diaphragms with compressive residual stress on top of insulated counter electrodes. FEM (Finite Element Method) calculation shows that a sensing diaphragm with residual stress can...
Most of the MEMS inertial switches developed in recent years are intended for shock and impact sensing above 40 g. These switches are fabricated based on non-silicon surface micromachining with multiple steps of electroplating. In this paper, a silicon based low-g inertial switch typically used for linear acceleration sensing is designed and fabricated. The inertial switch consists of a high volume...
This paper presents the design of a novel multiple-shell vibratory ring gyroscope with increased capacitance for actuation and detection. The multiple shell ring gyroscope is formed as several concentering cylindrical shells with enough space between them to place electrodes in the middle. The structure yields in-plane degenerate flexural modes that are utilized to sense rotation along the normal...
In this study, we propose a novel dye-sensitized solar cell (DSSC) structure that employs a quantum dot/semiconductor silicon (QD/Si) coaxial nanorod array to replace the conventional dye/TiO2/TCO photoelectrode. We replaced the backlight input mode with top-side illumination and used a quantum dot to replace dye as the light-absorbing material. Photon-excited photoelectrons can be effectively transported...
We report a technique for defining high aspect ratio electrostatic gaps in micromachined glassblown spherical resonators. The approach is based on intentionally allowing a physical contact between the resonator and electrode structure, hence “collapsed electrodes”, then releasing and metalizing the electrodes and resonator. We utilized 500 um SOI electrodes in the glassblowing fabrication process,...
A piezoelectric MEMS with wake up function, Power down interrupt generator (PDIG), for inertial sensor systems is reported. The aluminum nitride based MEMS generates electric signals intrinsically in result of an inertial accelerations. The PDIG is optimized for maximum charge and voltage sensitivity. The charge sensitivity for a single electrode designed PDIG is measured with 40.1 pC/g and the maximum...
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