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In this paper, the amplitude and frequency stability of a mode-localized sensor are characterized in a closed loop setup. The system describes an absolute amplitude ratio sensitivity of 5250 to stiffness perturbations in linear operation. A stability of 432ppm at 500s integration time is observed for amplitude ratio measurements. A resolution of 85ppb corresponding to normalised stiffness perturbations...
Quartz tuning forks (QTFs) have been successfully employed as piezoelectric optoacoustic transducers in a quartz enhanced photoacoustic spectroscopic sensor (QEPAS) for sensitive and selective gas sensing applications. Stainless tubes are acoustically coupled with the QTF and act as an acoustic micro-resonator (AmR) to confine the acoustic waves and enhance the QEPAS signal [1]. Very recently, we...
In this paper, a sensorless active damping scheme of LCL-filter is proposed in grid-connected parallel inverters for battery energy storage systems. The proposed damping method is superior to the conventional notch filter and virtual damping methods with respect of robustness on the variation of resonance of the filter and unnecessary additional current sensors. The theoretical analysis of the proposed...
In this paper different methods to measure torque ripples in electrical machines are examined. Special focus is on capturing harmonics of the output torque in high-speed ranges. The proposed method offers a possibility to capture torque ripples over a wide frequency range. Compared to classical torque sensors, the measurement bandwidth is increased by a factor of seven.
In this paper, a novel technology is presented in which organic substrate manufacturing is used to create sensors and actuators directly in the CPU package. The dielectric material surrounding some interconnect traces in the substrate is removed, allowing those traces to act as sensors and actuators, while the CPU itself is used for signal processing and conditioning. To demonstrate proof of concept,...
We present a low-cost position sensing module based on a commercial Inductance-to-Digital Converter (LDC) that is applied to bearingless motor suspension control. The sensing module uses four LDC evaluation boards to differentially measure the x- and y-positions of the rotor. Each of the evaluation boards consists of an LDC chip, a sensing coil, and an on-board capacitor. The LDC chip drives the sensing...
Thickness control data measured at different fabrication stages of atomic force microscopy (AFM) self-sensing cantilevers are presented in this paper. Specifically, the thicknesses of multilayered structures comprising silicon, silicon dioxide and thin patterned layers have been measured in-line during multi-step devices' processing. The data of the electrically detected resonance frequencies of the...
We provide and discuss experimental data on the mass sensitivity of Rayleigh surface acoustic wave (RSAW) two-port resonators (TPR) as an alternative to the quartz crystal microbalance (QCM) for thickness measurements and characterization of extremely thin dielectric layers — in the sub nm to a few tens of nm range where a QCM does not provide sufficient sensitivity. The calibration process is performed...
A paper-based electromechanical system (PB-EMS) driven by means of the Lorentz force excitation method is introduced in this work. Such a system consists of a paper-based cantilever beam that is fabricated using conventional printer paper, printable electronics, and standard cutting tools. The results show the feasibility to develop PB-EMS using the Lorentz force actuation principle. In addition,...
Multiphase measurement is still a challenge in the petroleum industry, and water cut measurement is a particular problem. Resonant Cavity Sensors (RCS) have been employed to measure water cut in water-oil and water-gas flows. The noninvasive and nondestructive characteristic of this technology is one of its main advantages, since the sensors do not interfere in the flow and do not change its physical...
The use of vibration mode localization in arrays of mechanically-coupled, nearly identical cantilevers has been studied for ultra-sensitive mass detection and analyte identification. The effects of geometrical design of the coupling overhang, cantilever length, as well as the number of identical coupled cantilevers on the magnitude enhancement with a small mass perturbation were previously reported...
To enhance the miniaturization of the single-sided resonators, and to overcome the drawbacks in using broadside resonators, the Edge-Coupled Spiral Resonator (EC-SR) is proposed and implemented as near-field sensor. A prototype is fabricated and tested by sensing different liquids and organic tissues. The results validate the possibility to use the proposed resonator in designing sensors for biomedical...
The round trip time of the light pulse limits the maximum detectable frequency response range of vibration in phase-sensitive optical time domain reflectometry (φ-OTDR). We propose a method to break the frequency response range restriction of φ-OTDR system by modulating the light pulse interval randomly which enables a random sampling for every vibration point in a long sensing fiber. This sub-Nyquist...
Pound-Drever-Hall (PDH) technique has been widely adopted for ultrahigh resolution fiber-optic sensors, but its performance degenerates seriously as the light power drops. To solve this problem, we developed a coherent PDH technique for weak optical signal detection, with which the signal-to-noise ratio (SNR) of demodulated PDH signal is dramatically improved. In the demonstrational experiments, a...
In this paper, a novel Micro Electro Mechanical System (MEMS) based cantilever beam of cross section (400×150×1)μm is presented for the detection of Metronidazole (MZN) which can be used in food processing industry to detect its toxicity level in meat. MZN is a drug that is proven to be carcinogenic if used as feed addictive for cattle breeding or aquafarming. Molecular imprinted Gold cantilever beam...
The resonance frequencies (eigenvalues) and amplitudes (eigenvectors) of coupled micro/nano-resonator arrays are used in sensors to measure applied physical perturbations such as mass. A higher sensitivity is obtained by measuring amplitude changes rather than frequency variations corresponding to identical perturbations. In this paper we present a new technique by measuring the difference of displacement...
We utilise an inverse eigenvalue analysis technique with perturbation analysis to characterise the sensing performance of two coupled MEMS resonators under manufacturing variability. The analysis derives the operating point, sensitivity, linearity, and mass resolution of the experimentally observed performance of an array of two resonators for both eigenfrequency and eigenvector sensing techniques...
The use of vibration mode localization in arrays of mechanically-coupled, nearly identical beam-shaped resonators has been studied for ultra-sensitive mass detection. In this paper, for the first time, we thoroughly summarized and compared different sensitivities of various cantilever structures on mass sensing. Meanwhile, from our analytical results, the expression of the highest sensitivity has...
Mathematical model of a sensing device based on piezo resonator with changeable electrode gap is further developed. Dependences of resonance frequency and conductivity of the piezoelectric sensing device on parameters of movable electrode formed by a cylindrical surface for which one of hyperbole branches serves as guide are obtained. Grading characteristics in the form of dependence of frequency...
Miniaturized sensor's exhibit fast responses with minimal sample volume and feasibility of mass production. The Micro-cantilever based sensor detection scheme has been proved as a potential technology for sensing chemical and biological agents with high sensitivity and selectivity. The geometrical variation and dimensional scalability are the major adaptation techniques in order to achieve the trade...
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