Author
Zhao Zhang
Bio: Zhao Zhang is an academic researcher from Northwestern Polytechnical University. The author has contributed to research in topics: Lorentz force & Magnetometer. The author has an hindex of 1, co-authored 2 publications receiving 3 citations.
Topics: Lorentz force, Magnetometer, Amplitude, Materials science, Capacitor
Papers
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23 Jun 2019
TL;DR: In this article, the amplitude ratio (AR) instead of the frequency was used as the readout metric, and the sensitivity of AR was 7800 times higher than that of frequency.
Abstract: This paper for the first time reports a resonant magnetometer based on the mode localization phenomenon. The proposed sensor utilizes a 3 degrees-of-freedom (DoF) weakly coupled resonators (WCRs) as the mechanical sensing element, with massive grill structures on both sides for converting magnetic field strength to stiffness perturbation. Stiffness perturbation will cause a drastic variation in the mode shape owing to the mode localization phenomenon. We use the amplitude ratio (AR) instead of the frequency as the readout metric, and the sensitivity of AR is 7800 times higher than that of frequency. And the best resolution of the magnetometer is 1.6μT/√Hz in the range of 90mT.
7 citations
TL;DR: In this article, a DC electric field sensor (EFS) based on the mode localization phenomenon is presented. But the sensor is not suitable for the use in the wireless communication applications, as it requires a large number of capacitors to be coupled with the WCRs.
Abstract: This paper reports a DC electric field sensor (EFS) based on the mode localization phenomenon. The EFS consists of 3-degrees-of-freedom weakly coupled resonators (WCRs) and two capacitor arrays that are electrostatically coupled with the WCRs. The capacitor arrays sense the electric field and produce a stiffness perturbation that causes an amplitude ratio change of the WCRs. The EFS is fabricated using a silicon-on-insulator process and evaluated in a vacuum chamber. The amplitude ratio of the resonators changes from 2.2 to 7.5 as the electric field strength ranges from 0 to 7 kV/m, with a sensitivity of 0.76 /(kV/m). The noise, resolution, and stability of the mode-localized EFS are 11.5 (V/m)/√Hz, 22.9 V/m, and 9.1 V/m, respectively, which are competitive compared with that of other high-performance micromachined EFS.
1 citations
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23 Mar 2020
TL;DR: In this paper, a mode-localized resonant tilt sensor based on 3 degree-of-freedom (DoF) weakly coupled resonators (WCRs) is proposed.
Abstract: In this paper, we propose a mode-localized resonant tilt sensor based on 3 degree-of-freedom (DoF) weakly coupled resonators (WCRs). The angle of rotation around the sensing axis causes gravity perturbation to the two outer resonators and influences the energy distribution of the WCRs system, finally resulting in a drastic change of the mode shape. The experimental results indicate that the sensitivity is improved by 326% compared with the 2-DoF mode-localized resonant tilt sensor. Under the closed-loop test, the resolution of the tilt sensor can achieve 2.4e-5 degrees within the range of 50 degrees.
8 citations
01 Jan 2020
TL;DR: In this article, a mode-localized magnetometer with 3 degrees-of-freedom (DOF) weakly coupled resonators coupled by F-shaped coupling beams is presented.
Abstract: This paper reports a mode-localized magnetometer with novel 3 degrees-of-freedom (DOF) weakly coupled resonators (WCRs) coupled by F-shaped coupling beams. In this coupling mechanism, the direct coupling between the two outer resonators can be effectively suppressed, which decreases the coupling coefficient and drastically increases the sensitivity. Utilizing these novel WCRs for Lorentz force sensing, a magnetometer is realized with the resolution of $6.9\ \text{nT}/\surd \text{Hz}$ in the range of 100 mT, which is an improvement of 234.78 times that of state-of-the-art mode-localized magnetometers ( $1.62\ \mu \mathrm{T}/\surd\text{Hz}$ ).
3 citations
TL;DR: It is shown, both theoretically and experimentally, that this condition yields higher sensitivities and similar sensitivity ranges than that of resonance peak tracking while being less time consuming than a classical open-loop configuration due to the absence of frequency sweep.
Abstract: We present a mode localized mass sensor prototype based on a hybrid system excited at a fixed frequency slightly below the resonances. Indeed, we show, both theoretically and experimentally, that this condition yields higher sensitivities and similar sensitivity ranges than that of resonance peak tracking while being less time consuming than a classical open-loop configuration due to the absence of frequency sweep. The system is made of a quartz resonator and a hardware that includes a resonator and the coupling. The digital aspect allows maximum sensitivity to be achieved with a fine tuning of the different parameters and the implementation of a coupling, regardless of the physical resonator geometry. This allows the generation of mode localization on shear waves resonant structures such as the quartz cristal microbalance widely used in biosensing. This solution has been successfully implemented using resin micro balls depositions. The sensitivities reach almost their maximum theoretical values which means this fixed frequency method has the potential to reach lower limit of detection than the open loop frequency tracking method.
3 citations
TL;DR: In this article , a mode-localized ΔE-effect magnetic sensor model is established theoretically and numerically based on the designed weakly coupled resonators with multi-layer film structure.
Abstract: A mode-localized ΔE-effect magnetic sensor model is established theoretically and numerically. Based on the designed weakly coupled resonators with multi-layer film structure, it is investigated how the ΔE-effect of the magnetostrictive film under the external magnetic field causes the stiffness perturbation of the coupled resonators to induce the mode localization effect. Using the amplitude ratio (AR) as the output in the mode-localized ΔE-effect magnetic sensor can improve the relative sensitivity by three orders of magnitude compared with the traditional frequency output, which has been verified by simulations based on the finite element method (FEM). In addition, the effects of material properties and geometric dimensions on sensor performance parameters, such as sensitivity, linear range, and static operating point are also analyzed and studied in detail, providing the theoretical basis for the design and optimization of the mode-localized ΔE-effect magnetic sensor in different application scenarios. By reasonably optimizing the key parameters of the weekly coupled resonators, a mode-localized ΔE-effect magnetic sensor with the sensitivity of 18 AR/mT and a linear range of 0.8 mT can be achieved.
1 citations
DOI•
TL;DR: In this article , a sensing theory is derived to predict the amplitude-frequency curve with respect to the effect of mass perturbation, where high linearity is observed for both amplitude changes and frequency shifts.
Abstract: This article clarifies a high-sensitivity mass sensing mechanism, intrinsically correlated with energy relocalization. A sensing theory is derived to predict the amplitude–frequency curve with respect to the effect of mass perturbation, where high linearity is observed for both amplitude changes and frequency shifts. A localization factor is defined to characterize the degree of the energy localization, and its physical rationality is demonstrated with a coupled three-beam array as an example. A higher detection sensitivity via energy relocalization, increased by about 123.8% based on the amplitude change and by 250% based on the localization factor, is experimentally obtained with a high vibration amplitude compared to a low one. A mass sensing-warning scheme is further proposed for low-concentration monitoring and high-concentration warning, applicable to the detection and warning of a gas leak, dust pollution, harmful chemicals, and so on.