A Novel DC Current Sensor Using SMA Controlled Piezoelectric Bimorph Cantilever

2016 ◽  
Author(s):  
Suresh Kaluvan ◽  
Haifeng Zhang
Keyword(s):  
Resonant Frequency ◽  
Cantilever Beam ◽  
Shape Change ◽  
Piecewise Linear ◽  
High Sensitivity ◽  
Electrical Current ◽  
Sensor System ◽  
Current Sensor ◽  
Piezo Actuator ◽  
Current Sensing

A new approach to measure direct current (DC) using shape memory alloy (SMA) tuning piezo cantilever resonant frequency technique is proposed in this work. The proposed current sensor system is designed using an electrically insulated SMA wire surface mounted on the cantilever beam with piezoelectric actuator. The cantilever beam is maintained at resonance using a closed loop piezo resonator circuit and the current ‘I’ to be measured is given to the SMA wire. The current induced temperature change of the SMA wire produces a mechanical shape change and produces a stiffness change to the resonating cantilever beam. The shift in resonant frequency due to the stiffness change is measured, which is related to the input electrical current ‘I’ to the SMA wire. The key enabling concept of this proposed work is to alter the cantilever resonant frequency using the shape changing property of SMA wire with input unknown electric current. The analytical model of the current sensor system is derived and the results are compared with the experimental results. The SMA coupled with piezo actuator based resonant current sensing system is evaluated for the input current range of 0 to 0.5A. The proposed current sensing concept is simple and completely novel and it is found that it has very high sensitivity to current and result is piecewise linear.

scholarly journals Nano and Microsensors for Mammalian Cell Studies

Micromachines ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 439 ◽  
Author(s):  
Ioana Voiculescu ◽  
Masaya Toda ◽  
Naoki Inomata ◽  
Takahito Ono ◽  
Fang Li
Keyword(s):  
Resonant Frequency ◽  
Cantilever Beam ◽  
Mammalian Cell ◽  
Temperature Sensor ◽  
Mammalian Cells ◽  
High Sensitivity ◽  
Biological Applications ◽  
Impedance Sensing ◽  
Frequency Regime ◽  
Response To Temperature

This review presents several sensors with dimensions at the nano- and micro-scale used for biological applications. Two types of cantilever beams employed as highly sensitive temperature sensors with biological applications will be presented. One type of cantilever beam is fabricated from composite materials and is operated in the deflection mode. In order to achieve the high sensitivity required for detection of heat generated by a single mammalian cell, the cantilever beam temperature sensor presented in this review was microprocessed with a length at the microscale and a thickness in the nanoscale dimension. The second type of cantilever beam presented in this review was operated in the resonant frequency regime. The working principle of the vibrating cantilever beam temperature sensor is based on shifts in resonant frequency in response to temperature variations generated by mammalian cells. Besides the cantilever beam biosensors, two biosensors based on the electric cell-substrate impedance sensing (ECIS) used to monitor mammalian cells attachment and viability will be presented in this review. These ECIS sensors have dimensions at the microscale, with the gold films used for electrodes having thickness at the nanoscale. These micro/nano biosensors and their mammalian cell applications presented in the review demonstrates the diversity of the biosensor technology and applications.

High Current 270 VDC Contactor and Current Sensor System Design and Development

1998 ◽  
Author(s):  
Sean Sande ◽  
Karl Kitts ◽  
Robert Shanebrook ◽  
Dennis Timm ◽  
Tuan N. Tran
Keyword(s):  
System Design ◽  
Sensor System ◽  
Current Sensor ◽  
High Current ◽  
Design And Development ◽  
Sensor System Design

scholarly journals Time-Multiplexed Self-Powered Wireless Current Sensor for Power Transmission Lines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Current Measurement ◽  
Current Sensor ◽  
Power Transmission Line ◽  
Power Transmission Lines ◽  
Current Sensing ◽  
Self Powered

Current measurement is a key part of the monitoring system for power transmission lines. Compared with the conventional current sensor, the distributed, self-powered and contactless current sensor has great advantages of safety and reliability. By integrating the current sensing function and the energy harvesting function of current transformer (CT), a time-multiplexed self-powered wireless sensor that can measure the power transmission line current is presented in this paper. Two operating modes of CT, including current sensing mode and energy harvesting mode, are analyzed in detail. Through the design of mode-switching circuit, harvesting circuit and measurement circuit are isolated using only one CT secondary coil, which eliminates the interference between energy harvesting and current measurement. Thus, the accurate measurement in the current sensing mode and the maximum energy collection in the energy harvesting mode are both realized, all of which simplify the online power transmission line monitoring. The designed time-multiplexed working mode allows the sensor to work at a lower transmission line current, at the expense of a lower working frequency. Finally, the proposed sensor is verified by experiments.

scholarly journals Eddy Current Sensor System for Tilting Independent In-Process Measurement of Magnetic Anisotropy

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2652
Author(s):  
Frank Wendler ◽  
Rohan Munjal ◽  
Muhammad Waqas ◽  
Robert Laue ◽  
Sebastian Härtel ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Eddy Current ◽  
Digital Signal ◽  
Production Equipment ◽  
Sensor System ◽  
Current Sensor ◽  
Cold Forming ◽  
Eddy Current Sensor ◽  
Two Samples ◽  
Internal Mechanical Stress

Modern production equipment is based on the results of quality control as well as process parameters. The magnetic anisotropy of materials is closely connected to internal mechanical stress by the Villari effect, and also to hardening effects due to plastic deformations, and could therefore provide an interesting basis for process control. Nevertheless, the analysis of anisotropic properties is extremely sensitive to sensor and workpiece misalignments, such as tilting. In this work, a novel eddy current sensor system is introduced, performing a non-contact measurement of the magnetic anisotropy of a workpiece and realizing a separation and correction of tilting effects. The measurement principle is demonstrated with the example of two samples with different magnetic anisotropy values induced by cold forming. Both samples are analyzed under different tilt angles between the sensor axis and the surface of the workpiece. In this work, digital signal processing is demonstrated on the acquired raw data in order to differentiate the effects of tilt and of anisotropy, with the use of preliminary results as an example of two prepared samples.

scholarly journals Complex Permittivity Characterization of Liquid Samples Based on a Split Ring Resonator (SRR)

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3385
Author(s):  
Jialu Ma ◽  
Jingchao Tang ◽  
Kaicheng Wang ◽  
Lianghao Guo ◽  
Yubin Gong ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Complex Permittivity ◽  
Ring Resonator ◽  
High Sensitivity ◽  
Split Ring Resonator ◽  
Debye Model ◽  
Split Ring ◽  
Liquid Samples ◽  
Microwave Sensor

A complex permittivity characterization method for liquid samples has been proposed. The measurement is carried out based on a self-designed microwave sensor with a split ring resonator (SRR), the unload resonant frequency of which is 5.05 GHz. The liquid samples in capillary are placed in the resonant zone of the fabricated senor for high sensitivity measurement. The frequency shift of 58.7 MHz is achieved when the capillary is filled with ethanol, corresponding a sensitivity of 97.46 MHz/μL. The complex permittivity of methanol, ethanol, isopropanol (IPA) and deionized water at the resonant frequency are measured and calibrated by the first order Debye model. Then, the complex permittivity of different concentrations of aqueous solutions of these materials are measured by using the calibrated sensor system. The results show that the proposed sensor has high sensitivity and accuracy in measuring the complex permittivity of liquid samples with volumes as small as 0.13 μL. It provides a useful reference for the complex permittivity characterization of small amount of liquid chemical samples. In addition, the characterization of an important biological sample (inositol) is carried out by using the proposed sensor.

Magnet-sensitive optical fiber and its application in current sensor system

1991 ◽  
Author(s):  
Tong Yu ◽  
Qin G. Li ◽  
Rongsheng Chen ◽  
Jin-Li Yan
Keyword(s):  
Optical Fiber ◽  
Sensor System ◽  
Current Sensor

High transparency flexible sensor for pressure and proximity sensing

2018 ◽  
Vol 32 (32) ◽  
pp. 1850394 ◽  
Author(s):  
Dan Bu ◽  
Si Qi Li ◽  
Yun Ming Sang ◽  
Cheng Jun Qiu
Keyword(s):  
Indium Tin Oxide ◽  
Pressure Range ◽  
Piecewise Linear ◽  
High Sensitivity ◽  
Maximum Error ◽  
Piecewise Linear Function ◽  
Good Repeatability ◽  
Flexible Pressure Sensor ◽  
Human Finger ◽  
Proximity Sensing

A high-sensitivity and high-transmittance flexible pressure sensor is presented in this paper. Using polydimethylsiloxane (PDMS) sensing film to cover indium tin oxide (ITO) electrodes interdigitated on the polyethylene terephthalate (PET) substrate, an interdigital capacitance (IDC) structure is constructed. The pressure and proximity sensing characteristics of the fabricated IDC sensor are investigated. The experiment results show that the IDC sensor has the piecewise linear function in different pressure range, especially sensitive to the low-pressure range with the pressure sensitivity of 6.64 kPa[Formula: see text]. Moreover, it has a good repeatability with the maximum error rate of 2.73% and a high transmittance over 90% in the wavelength range from 400 nm to 800 nm. As a human finger approaches or leaves, the proximity sensing characteristic emerges, with a maximum sensing distance of about 20 cm.

scholarly journals Compact Tb doped fiber optic current sensor with high sensitivity

2015 ◽  
Vol 23 (23) ◽  
pp. 29993 ◽  
Author(s):  
Duanni Huang ◽  
Sudharsanan Srinivasan ◽  
John E. Bowers
Keyword(s):  
Fiber Optic ◽  
High Sensitivity ◽  
Current Sensor
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