A Bulk Micromachined Si-on-Glass Tunneling Accelerometer

2007 ◽  
Author(s):  
Min Miao ◽  
Qifang Hu ◽  
Yilong Hao ◽  
Haifeng Dong ◽  
Haixia Zhang
Keyword(s):  
Closed Loop ◽  
Proof Mass ◽  
Anodic Bonding ◽  
Analysis And Design ◽  
Icp Etching ◽  
Highly Sensitive ◽  
Out Of Plane ◽  
Input Range ◽  
Pyrex 7740 ◽  
Si Wafer

A bulk micromachined tunneling accelerometer on Pyrex 7740 substrate is reported in this paper, which is intended for the applications in highly sensitive inertia measurements, such as those in microgravity environments and self-contained navigation. The tunneling tip is defined by an isotropic wet etching followed by a maskless wet thermal oxidation for the sharpening of the tip. Unlike the process ever reported by other facilities, an ICP etching on the side of the Si wafer with the tip is utilized to partially define the suspension and the proof mass before the anodic bonding of the Si wafer with the glass substrate, and an addition maskless ICP etching is used to release the whole movable structure after the bonding. Fabricated samples have displayed the effectiveness of the process proposed, which is relatively simple and may guarantee the yield of mass production. The theoretical analysis and design of the closed loop architecture of the device are demonstrated. Capable of sensing out-of-plane acceleration, this device has demonstrated a high resolution of 0.015mg/rtHz (@ 1∼100Hz) and a nonlinearity of less than 1% over ±1g input range.

scholarly journals Microcrack Detection Using Spectral Response Data Alone

2021 ◽  
Vol 11 (8) ◽  
pp. 3655
Author(s):  
Gee-Soo Lee ◽  
Chan-Jung Kim
Keyword(s):  
Spectral Response ◽  
Coherence Function ◽  
Cold Forming ◽  
Response Data ◽  
Highly Sensitive ◽  
Bending Mode ◽  
Out Of Plane ◽  
Rectangular Specimen ◽  
Microcrack Detection ◽  
Impulse Force

Microcracks of depth less than 200 μm in mechanical components are difficult to detect because conventional methods such as X-ray or eddy current measurements are less sensitive to such depths. Nonetheless, an efficient microcrack detection method is required urgently in the mechanical industry because microcracks are produced frequently during cold-forming. The frequency response function (FRF) is known to be highly sensitive even to microcracks, and it can be obtained using both the input data of an impact hammer and the response data of an accelerometer. Under the assumption of an impulse force with a similar spectral impulse pattern, spectral response data alone could be used as a crack indicator because the dynamic characteristics of a microcrack may be dependent solely on these measured data. This study investigates the feasibility of microcrack detection using the response data alone through impact tests with a simple rectangular specimen. A simple rectangular specimen with a 200 μm microcrack at one face was prepared. The experimental modal analysis was conducted for the normal (uncracked) specimen and found-first bending mode about 1090 Hz at the X-Y plane (in-plane). Response accelerations were obtained in both at in-plane locations as well as X-Z plane (out-of-plane), and the crack was detected using the coherence function between a normal and a cracked specimen. A comparison of the crack inspection results obtained using the response data and the FRF data indicated the validity of the proposed method.

Design and Mobility Analysis of Large Deployable Mechanisms Based on Plane-Symmetric Bricard Linkage

2016 ◽  
Author(s):  
Xiaozhi Qi ◽  
Bing Li ◽  
Zhihuai Miao ◽  
Hailin Huang
Keyword(s):  
Computer Aided Design ◽  
Closed Loop ◽  
Degree Of Freedom ◽  
Mobility Analysis ◽  
Plane Symmetric ◽  
Analysis And Design ◽  
Geometric Conditions ◽  
Deployable Mechanism ◽  
Vertical Bars ◽  
Aided Design

In this paper, a class of large deployable mechanisms constructed by plane-symmetric Bricard linkage is presented. The plane-symmetric Bricard linkage is a closed-loop over-constrained spatial mechanism composed of six hinge-jointed bars, which has one plane of symmetry during its deployment process. The kinematic analysis of the linkage is presented from the perspectives of geometric conditions, closure equations and degree of freedom. The results illustrates that the linkage has one degree of freedom, and it can be deployed from the folded configuration to one rectangle plane. Therefore, the plane-symmetric Bricard linkage can be used to construct lager deployable mechanism as basic deployable unit. Four plane-symmetric Bricard linkages can be assembled to a quadrangular module by sharing the vertical bars of adjacent units. The module is a multi-loop deployable mechanism and has one degree of freedom by the mobility analysis. Large deployable mast, deployable plane truss and deployable ring are built by a plurality of plane-symmetric Bricard linkages. The computer-aided design models for typical examples are built to illustrate their feasibility and validate the analysis and design methods.

Highly sensitive infrared polarized photodetector enabled by out-of-plane PSN architecture composing of p-MoTe2, semimetal-MoTe2 and n-SnSe2

Nano Research ◽  
2021 ◽  
Author(s):  
Yiming Sun ◽  
Jingxian Xiong ◽  
Xuming Wu ◽  
Wei Gao ◽  
Nengjie Huo ◽  
...  
Keyword(s):  
Highly Sensitive ◽  
Out Of Plane

Simulation and Fabrication of Novel Polymeric Tunneling Sensor by Hot Embossing Technique

2002 ◽  
Author(s):  
Tianhong Cui ◽  
Kody Varahramyan ◽  
Yongjun Zhao ◽  
Jing Wang
Keyword(s):  
Aspect Ratio ◽  
Silicon Wafer ◽  
Optimum Design ◽  
High Aspect Ratio ◽  
Hot Embossing ◽  
Anodic Bonding ◽  
Glass Disk ◽  
Icp Etching ◽  
Sensor Platform ◽  
Polymer Microfabrication

This paper reports the simulation and fabrication of novel polymer-based tunneling sensors by hot embossing technique, one of the advanced polymer microfabrication technologies. ANSYS is the software tools used to simulate the mechanical microstructures of the polymer tunneling sensors. Following the optimum design of the sensors, the mold inserts of hot embossing are fabricated by anodic bonding of glass disk 5 mm think and silicon wafer, with high-aspect-ratio microstructures by ICP etching. Main structures of polymer-based tunneling sensors are hot embossed on PMMA, followed by plastic bonding to form lateral tunneling sensor platform.

HIGH-GAIN/EFFICIENCY MULTISTAGE SWITCHED-CAPACITOR-VOLTAGE-MULTIPLIER DC–DC CONVERTER

2012 ◽  
Vol 21 (03) ◽  
pp. 1250023
Author(s):  
YUEN-HAW CHANG
Keyword(s):  
Power Efficiency ◽  
Closed Loop ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Conversion Ratio ◽  
Switched Capacitor ◽  
Two Phase ◽  
Analysis And Design ◽  
Voltage Multiplier ◽  
Capacitor Voltage

A closed-loop interleaved multistage switched-capacitor-voltage-multiplier (mc × nc-stage SCVM) dc–dc converter is proposed by combining a variable-conversion-ratio (VCR) and pulse-width-modulation (PWM) control for low-power step-up conversion and high-efficiency regulation. In this SCVM, the power part is composed of two mc-stage SC cells (front) and two nc-stage SC cells (rear) in cascade, and these cells are operated by two-phase nonoverlapping clocks for an interleaved operation with voltage gain of mc × nc at most. This paper presents the VCR control to change the running stage number m,n and topological path for a more flexible and suitable gain level m × n (1 × 1, 2 × 1, 2 × 2, 3 × 1, 3 × 2, 3 × 3,…, mc × nc) according to the desired output so as to improve power efficiency, especially for the lower output. Besides, PWM is adopted not only to enhance output regulation for different outputs, but also to reinforce output robustness to source/loading variation. Further, some theoretical analysis and design include: SCVM model, steady-state analysis, conversion ratio, power efficiency, output ripple, stability, capacitance selection, and control design. Finally, the closed-loop SCVM is simulated, and the hardware is implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme.

Design and Mobility Analysis of Large Deployable Mechanisms Based on Plane-Symmetric Bricard Linkage

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Xiaozhi Qi ◽  
Hailin Huang ◽  
Zhihuai Miao ◽  
Bing Li ◽  
Zongquan Deng
Keyword(s):  
Computer Aided Design ◽  
Closed Loop ◽  
Singularity Analysis ◽  
Degree Of Freedom ◽  
Plane Symmetric ◽  
Analysis And Design ◽  
Geometric Conditions ◽  
Deployable Mechanism ◽  
Vertical Bars ◽  
Aided Design

In this paper, a class of large deployable mechanisms constructed by plane-symmetric Bricard linkages is presented. The plane-symmetric Bricard linkage is a closed-loop overconstrained spatial mechanism composed of six hinge-jointed bars, which has one plane of symmetry during its deployment process. The kinematic analysis of the linkage is presented from the perspectives of geometric conditions, closure equations, and degree-of-freedom. The results illustrate that the linkage has one degree-of-freedom and can be deployed from the folded configuration to one rectangle plane. Therefore, the plane-symmetric Bricard linkage can be used as a basic deployable unit to construct larger deployable mechanisms. Four plane-symmetric Bricard linkages can be assembled into a quadrangular module by sharing the vertical bars of the adjacent units. The module is a multiloop deployable mechanism and has one degree-of-freedom. The singularity analysis of the module is developed, and two methods to avoid singularity are presented. A large deployable mast, deployable plane truss, and deployable ring are built with several plane-symmetric Bricard linkages. The deployment properties of the large deployable mechanisms are analyzed, and computer-aided design models for typical examples are built to illustrate their feasibility and validate the analysis and design methods.

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