High-speed 3D optical imaging and failure analysis of high- and low-frequency movements in micro-electro-mechanical (MEMS) with nanometer resolution

2001 ◽  
Author(s):  
W. Merlijn van Spengen ◽  
Ingrid De Wolf ◽  
Bob Puers
Keyword(s):  
Failure Analysis ◽  
Optical Imaging ◽  
High Speed ◽  
Low Frequency ◽  
Nanometer Resolution

Nanoprobing Applications with Capacitance-Voltage and Pulsed Current-Voltage Measurements for Device Failure Analysis

2015 ◽  
Author(s):  
LiLung Lai ◽  
Nan Li ◽  
Qi Zhang ◽  
Tim Bao ◽  
Robert Newton
Keyword(s):  
Failure Analysis ◽  
High Speed ◽  
Pulsed Current ◽  
Electrical Measurements ◽  
Device Failure ◽  
Mos Devices ◽  
Atomic Force ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Rising Time

Abstract Owing to the advancing progress of electrical measurements using SEM (Scanning Electron Microscope) or AFM (Atomic Force Microscope) based nanoprober systems on nanoscale devices in the modern semiconductor laboratory, we already have the capability to apply DC sweep for quasi-static I-V (Current-Voltage), high speed pulsing waveform for the dynamic I-V, and AC imposed for C-V (Capacitance-Voltage) analysis to the MOS devices. The available frequency is up to 100MHz at the current techniques. The specification of pulsed falling/rising time is around 10-1ns and the measurable capacitance can be available down to 50aF, for the nano-dimension down to 14nm. The mechanisms of dynamic applications are somewhat deeper than quasi-static current-voltage analysis. Regarding the operation, it is complicated for pulsing function but much easy for C-V. The effective FA (Failure Analysis) applications include the detection of resistive gate and analysis for abnormal channel doping issue.

scholarly journals Research and Fabrication of Broadband Ring Flextensional Underwater Transducer

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1548
Author(s):  
Jiuling Hu ◽  
Lianjin Hong ◽  
Lili Yin ◽  
Yu Lan ◽  
Hao Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Structural Parameters ◽  
Low Frequency ◽  
Flexural Vibration ◽  
Underwater Acoustic Communication ◽  
Voltage Response ◽  
Water Tank ◽  
Spherical Cap ◽  
Finite Element Software ◽  
Underwater Transducer

At present, high-speed underwater acoustic communication requires underwater transducers with the characteristics of low frequency and broadband. The low-frequency transducers also are expected to be low-frequency directional for realization of point-to-point communication. In order to achieve the above targets, this paper proposes a new type of flextensional transducer which is constructed of double mosaic piezoelectric ceramic rings and spherical cap metal shells. The transducer realizes broadband transmission by means of the coupling between radial vibration of the piezoelectric rings and high-order flexural vibration of the spherical cap metal shells. The low-frequency directional transmission of the transducer is realized by using excitation signals with different amplitude and phase on two mosaic piezoelectric rings. The relationship between transmitting voltage response (TVR), resonance frequency and structural parameters of the transducer is analyzed by finite element software COMSOL. The broadband performance of the transducer is also optimized. On this basis, the low-frequency directivity of the transducer is further analyzed and the ratio of the excitation signals of the two piezoelectric rings is obtained. Finally, a prototype of the broadband ring flextensional underwater transducer is fabricated according to the results of simulation. The electroacoustic performance of the transducer is tested in an anechoic water tank. Experimental results show that the maximum TVR of the transducer is 147.2 dB and the operation bandwidth is 1.5–4 kHz, which means that the transducer has good low-frequency, broadband transmission capability. Meanwhile, cardioid directivity is obtained at 1.4 kHz and low-frequency directivity is realized.

Measurement of Dynamic Strain

1943 ◽  
Vol 10 (2) ◽  
pp. A85-A92
Author(s):  
C. O. Dohrenwend ◽  
W. R. Mehaffey
Keyword(s):  
High Speed ◽  
Shock Loading ◽  
Low Frequency ◽  
Dynamic Strain ◽  
Time Axis ◽  
Low Frequencies ◽  
Strain Measurements ◽  
Moving Vehicles ◽  
Machine Parts ◽  
Dynamic Strains

Abstract The measurement of dynamic strains of both high and low frequency give rise to a variety of problems in instrumentation. Two types of equipment and circuits designed and used by the authors are discussed in detail. The first type based on the amplitude-modulated method is for low frequencies from zero to about 15 per cent of the carrier frequency of 1025 cycles per sec. The equipment has application to strain measurements varying from static values to those produced in moving vehicles, various machine parts, structures such as crane bridges, in fact all strain measurements where the frequency is 150 cycles per sec or less. The second type of equipment discussed is a potentiometer type and is for high-frequency strain measurements from 100 cycles per sec to 8000 cycles per sec. This high-speed equipment is conveniently used for impact strain, such as produced in hammer blows, shock loading, forging equipment, and impact-factor determination. Both units are designed to be used with a cathode-ray oscillograph which lends itself to a variety of recording methods. The methods discussed include both the type where the time axis is obtained by sweeping the oscilloscope beam on a stationary film and where the time axis is obtained mechanically.

Study on bearing structure and joint seismic resistance of large span non-landing arch on high-speed railway station

2019 ◽  
Author(s):  
Liu Chuanping ◽  
Tianluan Liu ◽  
Jian Jia
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Large Earthquake ◽  
Scale Model ◽  
Railway Station ◽  
High Speed Railway ◽  
Long Span ◽  
Weak Component ◽  
Double Beam ◽  
Cyclic Loading Tests

<p>The main entrance of Chongqing West Railway Station adopts the non-landing compound arch with a span of 108m. In this paper, the nonlinear finite element theory is applied to analyze the bearing capacity and seismic ductility of the compound arch joints. Low frequency cyclic loading tests are performed on the 1/5 scale model. Based on the calculation and test results, a double beam structure and a section of steel truss are placed in the arch joints to bear the force of the arch. Moreover, the buckling-restrained brace (BRB) is placed in the lower part of the arch that enables most force directly transmit to the foundation of the arch. Unlike BRB’s common use as an inter-column support, it now acts as a buckling constraint support in the large earthquake. For instance, it can be yielded before the frame column to improve earthquake resistance. The research results indicate that the compound arch joint structure successfully accomplishes the seismic design goals of strong joints with weak component. Moreover, the study provides the theoretical basis and design reference for the application of BRB and long-span arch structures in high-speed railway station.</p>

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