Measurement of composition of mixtures at high pressures with high sensitivity using frequency response of microcantilevers (Conference Presentation)

2018 ◽  
Author(s):  
Shadi Khan Baloch ◽  
Alper Kiraz ◽  
Alexandr Jonáš ◽  
B. Erdem Alaca ◽  
Can Erkey
Keyword(s):  
Frequency Response ◽  
High Pressures ◽  
High Sensitivity

scholarly journals Transparent and Flexible Vibration Sensor Based on a Wheel-Shaped Hybrid Thin Membrane

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1246
Author(s):  
Siyoung Lee ◽  
Eun Kwang Lee ◽  
Eunho Lee ◽  
Geun Yeol Bae
Keyword(s):  
Frequency Response ◽  
High Sensitivity ◽  
Vibration Sensor ◽  
Human Machine Interaction ◽  
High Transparency ◽  
Vibration Sensors ◽  
Low Stiffness ◽  
Machine Interaction ◽  
The Internet Of Things ◽  
Ultrathin Membranes

With the advent of human–machine interaction and the Internet of Things, wearable and flexible vibration sensors have been developed to detect human voices and surrounding vibrations transmitted to humans. However, previous wearable vibration sensors have limitations in the sensing performance, such as frequency response, linearity of sensitivity, and esthetics. In this study, a transparent and flexible vibration sensor was developed by incorporating organic/inorganic hybrid materials into ultrathin membranes. The sensor exhibited a linear and high sensitivity (20 mV/g) and a flat frequency response (80–3000 Hz), which are attributed to the wheel-shaped capacitive diaphragm structure fabricated by exploiting the high processability and low stiffness of the organic material SU-8 and the high conductivity of the inorganic material ITO. The sensor also has sufficient esthetics as a wearable device because of the high transparency of SU-8 and ITO. In addition, the temperature of the post-annealing process after ITO sputtering was optimized for the high transparency and conductivity. The fabricated sensor showed significant potential for use in transparent healthcare devices to monitor the vibrations transmitted from hand-held vibration tools and in a skin-attachable vocal sensor.

scholarly journals Optimization of Transformer Winding Deformation Assessment Criterion Considering Insulation Aging and Moisture Content

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6491
Author(s):  
Qian Wu ◽  
Yizhuo Hu ◽  
Ming Dong ◽  
Bo Song ◽  
Changjie Xia ◽  
...  
Keyword(s):  
Moisture Content ◽  
Frequency Response ◽  
High Sensitivity ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Response Curves ◽  
Insulation Aging ◽  
Transformer Winding ◽  
Winding Deformation ◽  
Paper Insulation

Frequency response analysis is widely used to diagnose transformer winding deformation faults due to its high sensitivity, strong anti-interference capability, and equipment portability, but the results of frequency response analysis can be affected by insulation aging and moisture in the transformer, leading to errors in the diagnosis of winding deformation faults. Currently, there is no effective method to prevent such errors. This paper focuses on optimizing the criterion for diagnosing winding deformations when insulation aging and moisture are present. First, the winding frequency response curves of oil-paper insulation were determined by combining insulation aging and moisture tests of the oil-paper insulation with frequency response simulations of the transformer winding. Next, the winding deformation criterion predicting the likelihood and extent of errors diagnosing transformer winding deformations due to the insulation aging and moisture content is discussed. Finally, the corresponding criterion optimization method is proposed. The corresponding results show that insulation aging and moisture can lead to errors when using the correlation coefficient R criterion to diagnose the transformer winding deformations. Moreover, the possibility of winding deformation errors caused by the change of insulation state can be reduced by introducing the corresponding auxiliary criterion through comparing the capacitance change rate based on the frequency response method and that based on the dielectric spectrum method.

scholarly journals Frequency Response Stabilization and Comparative Studies of MET Hydrophone at Marine Seismic Exploration Systems

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1944 ◽  
Author(s):  
Egor Egorov ◽  
Anna Shabalina ◽  
Dmitry Zaitsev ◽  
Sergey Kurkov ◽  
Nikolay Gueorguiev
Keyword(s):  
Frequency Response ◽  
Field Tests ◽  
High Sensitivity ◽  
Seismic Exploration ◽  
Joint Stock Company ◽  
Experimental Sample ◽  
Frequency Range ◽  
Stock Company ◽  
Low Frequencies ◽  
Marine Seismic

Low frequency hydrophone with a frequency range of 1−300 Hz for marine seismic exploration systems has been developed. The operation principle of the hydrophone bases on the molecular electronic transfer that allows high sensitivity and low level self-noise at low frequencies (<10 Hz) to be achieved. The paper presents a stabilization method of the frequency response within the frequency range at a depth up to 30 m. Laboratory and marine tests confirmed the stated characteristics as well as the possibility of using this sensor in bottom marine seismic systems. An experimental sample of the hydrophone successfully passed a comparative marine test at Gelendzhik Bay (Black Sea) with the technical support of Joint-Stock Company (JSC) “Yuzhmorgeologiya”. One of the main results is the possibility of obtaining high-quality information in the field of low frequencies, which was demonstrated in the course of field tests.

Detection of Damage Extension in Cantilever Beams Using Change Ratio of Frequency Response Functions

2011 ◽  
Vol 50-51 ◽  
pp. 875-879
Author(s):  
Hai Lei Jia ◽  
Yin Zhao
Keyword(s):  
Frequency Response ◽  
Natural Frequencies ◽  
Dynamic Properties ◽  
Damage Index ◽  
High Sensitivity ◽  
Cantilever Beams ◽  
Response Functions ◽  
Full Spectrum ◽  
Structural Dynamic ◽  
Low Dimensional

Frequency response function (FRF) is a fundamental dynamic index, which is capable of reflecting structural dynamic properties using full-spectrum information. In spite of distinct merits over conventional modal parameters, the FRF has an observable drawback of multi-dimensionality, unsuited for damage characterization. Such a situation motivates an interesting subject, i.e., extracting low-dimensional, high-sensitivity damage index from the FRF. This study focuses on developing a valid damage index, called FRF change ratio, to detect extension of damage. An experiment towards cantilever beams is systemically conducted. The results show that the FRF change ratio can effectively reflects damage extension, and it is more sensitive than conventional natural frequencies. This new damage index holds promise for practical damage detection in beam-like structures.

Design and Analysis of Thermal-Bubble-Based Micromachined Accelerometer

Volume 3 ◽  
2004 ◽  
Author(s):  
Ke-Min Liao ◽  
Rongshun Chen ◽  
Bruce C. S. Chou
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Velocity Field ◽  
Numerical Simulations ◽  
Frequency Response ◽  
Proof Mass ◽  
Flow Behavior ◽  
High Sensitivity ◽  
The Other ◽  
High Flux

In this study, a novel thermal-bubble-based micromachined accelerometer with advantages of no proof mass, preferable frequency response, and high sensitivity is presented. Unlike the other techniques, the only moving element in the proposed device is a small thermal-bubble created by using a high flux heater to vaporize the liquid contained in the micro chamber. In order to improve the performance of the accelerometer, the basic physical characteristics of this sensor have been analyzed. Numerical simulations are conducted to study the heat transfer and fluid flow behavior of the device and to demonstrate the feasibility of our design. The temperature profile and the velocity field distribution under different applied acceleration have been acquired. Moreover, a method for manufacturing the accelerometer by using the techniques of micromachining is provided and the performance of the presented design has been examined. The results concluded that the proposed design has better response and sensitivity comparing to its counterparts.

Development of a Low Resistance Micro Electro Magnetic Distance Sensor Using High Aspect Ratio Photo Resist

2000 ◽  
Vol 12 (5) ◽  
pp. 552-558
Author(s):  
Xianhe Ding ◽  
◽  
Katsutoshi Kuribayashi ◽  
Takao Hashida
Keyword(s):  
Frequency Response ◽  
Electrical Resistance ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
High Signal ◽  
Metal Pipes ◽  
Thick Photoresist ◽  
Distance Sensor ◽  
Electro Magnetic ◽  
Output Characteristics

To maintain metal pipes, an electromagnetic coil is necessary as the detecting device of the eddy current change in metal due to pipe defects and as the distance sensor of the clearance between the detecting device and metal wall. This type of sensor should be thin and have a smaller diameter for detection by precise resolution and have large inductance and low electrical resistance for high sensitivity and high S/N. In this paper, for the above requirements, a new planar spiral type of coil for higher inductance, and thicker coil for reducing the electrical resistance by using ultra-thick photoresist SU-8 and Ni electroplating is proposed. Micromachining technology for the small size diameter and for automatic assembly was applied to microcoil fabrication. The Ni microcoil 300μm thick and 3mm in diameter was fabricated. The static distance characteristics and the frequency response were measured. Experiments show that the sensor of the 300μm thick coil has better output characteristics and linearity. High sensitivity, high signal-to-noise ratio and wide frequency response of the fabricated sensor have been measured to be 1.7v/mm, 75.6dB and 10Hz to 1000Hz, respectively, for 300μm thick coil. The position was controlled using the microcoil distance sensor.

Characterization of fluid mixtures at high pressures using frequency response of microcantilevers

2017 ◽  
Vol 261 ◽  
pp. 202-209 ◽  
Author(s):  
Gamze Eriş ◽  
Shadi Khan Baloch ◽  
Asuman Aşıkoğlu Bozkurt ◽  
Alexandr Jonáš ◽  
Alper Kiraz ◽  
...  
Keyword(s):  
Frequency Response ◽  
High Pressures ◽  
Fluid Mixtures
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