Article
Chemistry, Analytical
Andrei Enache, Florin Draghici, Florin Mitu, Razvan Pascu, Gheorghe Pristavu, Mihaela Pantazica, Gheorghe Brezeanu
Summary: This paper presents an innovative readout circuit for SiC-MOS capacitor sensors using a phase locked loop (PLL) architecture. The circuit accurately converts the sensor's small-signal capacitance affected by hydrogen into a proportional output voltage. Validation through simulations and experiments demonstrates the correct operation of the proposed readout circuit, which successfully measures hydrogen concentrations up to 1600 ppm with voltage variations similar to experimental C-V curves.
Article
Engineering, Electrical & Electronic
Haomiao Zhou, Jiajin Chen, Yanqun Fang, Zhengtao Xu, Kai Chang, Guoliang Yu, Mingmin Zhu, Yang Qiu
Summary: This work discusses the performance of a novel modulated magnetoelectric (ME) weak magnetic sensor that has ultra-high sensitivity, extremely weak direct current, and very low-frequency magnetic signal detection capacity. The study introduces the principle of a nonlinear modulated reading circuit suitable for portable applications of modulated ME sensors, and proposes a small low-noise modulated reading circuit. Experimental results show that the sensor's equivalent magnetic field noise meets the low-frequency magnetic field detection limit of the ME sensor unit. The proposed low-power miniaturized low-noise readout circuit and modulated ME sensor have excellent prospects in portable, multichannel, and high-volume industrial applications.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Elisa Sacco, Johan Vergauwen, Georges Gielen
Summary: This article presents a robust voltage-controlled oscillator (VCO)-based front end for multiplexed single-ended resistive sensor readout applications. The architecture features a highly digital and area-compact design, and ensures high robustness against supply and temperature variations. The direct conversion of the sensor input resistance enables high linearity and high resolution readout.
IEEE JOURNAL OF SOLID-STATE CIRCUITS
(2022)
Article
Engineering, Electrical & Electronic
Yuan Cheng Qian, Yen Yu Chao, Shen Iuan Liu
Summary: A sub-sampling phase-locked loop (SSPLL) with a sub-sampling delay-locked loop is proposed to extend the loop bandwidth and achieve low jitter.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2022)
Article
Acoustics
Jian Fang, Anthony Finn, Ron Wyber, Russell S. A. Brinkworth
Summary: This study proposes and demonstrates a biologically inspired vision approach for acoustic detection of unmanned aerial vehicles. By learning from the early vision system of insects, it significantly enhances the signal-to-noise ratios in complex, cluttered, and low-light scenes, thereby achieving the enhancement of acoustic patterns and suppression of noise. Compared with traditional techniques, this method extends the detectable distance and improves the accuracy of flight parameter estimation for small and medium-sized unmanned aerial vehicles.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Engineering, Electrical & Electronic
Xing Heng, Kai Wei, Tian Zhao, Zitong Xu, Qian Cao, Xiaofei Huang, Yueyang Zhai, Mao Ye, Wei Quan
Summary: In this study, a new model is established to analyze the noise mechanism caused by the fluctuations of probe light's polarization in a modulated optical rotation detection system (ORDS). It is discovered that residual probe photon spin polarization leads to transverse electron-spin polarization errors and extra coupling magnetic noise. A novel closed-loop system is proposed to reduce the electron-spin errors and suppress the noise. Experimental results show an improved angular sensitivity and measurement uncertainty with the closed-loop control.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Nanoscience & Nanotechnology
Chen Li, Mingshuo Zhen, Ke Wang, Lei Liu, Wenping Zhang, Yakun Wang, Xiangqian Fan, Wenyuan Hou, Jijun Xiong
Summary: Temperature sensors have received great attention for personal health care and disease diagnosis recently. However, developing reliable and highly sensitive temperature sensors that can convert physiological signals into easily readable signals in a convenient way remains a challenge. In this study, an integrated smart temperature sensor system is proposed, which uses a traditional temperature sensor and an electrochromic display for real-time visual detection of temperature. The system possesses durable and stable properties and has the potential to pave the way for developing interactive wearable electronics and intelligent robots as real-time temperature feedback systems.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Mechanics
Wangqiao Chen
Summary: This study is devoted to experimentally investigate the acoustic receptivity in the airfoil boundary layer using time-resolved particle image velocimetry method. The symmetric vortex shedding process is observed, and a hysteresis phenomenon is discovered with the increasing and decreasing wind speed. The author applies the Hilbert transform to show a space-wavenumber spectrum of wall-normal velocity fluctuations to locate resonance points, where acoustic pressure resonates with fluctuations in the boundary layer. The results demonstrate that acoustic reception can influence local velocity to increase and decrease the wavenumber before and after reaching resonance points. The trailing edge noise impacts on the airfoil boundary layer to control the system states and follows the same acoustic feedback loop as Arbey and Bataille's study.
Article
Nanoscience & Nanotechnology
Robert Horvath, Giuseppe Modica, Ines Ghorbel, Gregoire Beaudoin, Konstantinos Pantzas, Isabelle Sagnes, Aude Martin, Alfredo De Rossi, Sylvain Combrie, Remy Braive
Summary: We introduce a new method for a low phase noise electro-optomechanical oscillator working directly in the GHz frequency range. This nanoscale oscillator is made of gallium phosphide (GaP) and integrated on silicon-on-insulator circuitry. By utilizing the strong interaction between optical and mechanical modes, ultra-pure mechanical oscillations are achieved and imprinted on an optical carrier. Stabilization is accomplished with an integrated optoelectronic feedback loop, resulting in short-term stability with a linewidth of 0.7 Hz and long-term stability with an Allan deviation below 10(-7) Hz/Hz at 10 s averaging time.
Article
Neurosciences
Heiko Stecher, Annika Notbohm, Florian H. Kasten, Christoph S. Herrmann
Summary: Transcranial alternating current stimulation is an effective tool for exploring brain oscillations, with a weak alternating current applied between electrodes on the scalp to modulate targeted brain oscillations. While a fixed stimulation frequency is commonly used, this study introduced an intermittent closed loop stimulation protocol to adjust the stimulation frequency based on ongoing brain rhythms. Contrary to expectations, the results showed that only a fixed stimulation protocol led to a persistent increase in post-stimulation alpha power, highlighting the benefit of constant stimulation with a fixed frequency for producing persistent synaptic changes.
FRONTIERS IN HUMAN NEUROSCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Kaixuan Wang, Shu Gong, Yuxin Zhang, Lim Wei Yap, Wenlong Cheng
Summary: Researchers have developed an acoustic sensor inspired by mosquito antennae, which can detect sound signals with high sensitivity and has a wide sensing range and fast response capability.
Article
Engineering, Electrical & Electronic
Yasmine Hawwari, Jerome Antoni, Hugo Andre, Yosra Marnissi, Dany Abboud, Mohammed El-Badaoui
Summary: This article presents a practical solution to the problem of detecting spectral peaks in nonuniform spectra. A robust probabilistic approach is applied, where the histogram of trimmed spectral data is fitted with a truncated Gamma distribution. The estimated distribution parameters are used to derive a threshold through a hypothesis test. The proposed approach is robust as it formulates the distribution without peaks, regardless of the number of peaks in the spectral data. The authors also suggest a preprocessing step to handle nonuniform spectra, and the methodology is validated using simulated and experimental signals.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Chemistry, Analytical
Xianfa Cai, Lizhong Xu
Summary: This study designed and developed a room temperature ZnO nanowire resonator with ultrahigh resonant frequency, real-time detection, and high precision. The closed-loop detection system was used to perform tests and analyze the frequency accuracy and phase noise.
Article
Engineering, Electrical & Electronic
Hyunsu Park, Jincheol Sim, Yoonjae Choi, Jonghyuck Choi, Youngwook Kwon, Chulwoo Kim
Summary: This paper presents a phase rotator-based delay-locked loop for a dynamic random-access memory interface in 28-nm CMOS technology. By using a sub-sampling technique, the timing mismatch of a replica delay line is reduced for synchronizing the input and output clocks. The proposed DLL utilizes a phase rotator delay line with an 8-phase clock generator for linearity to reduce the phase difference.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2022)
Article
Engineering, Mechanical
Ma del Rosario Bautista-Morales, L. D. Patino-Lopez
Summary: This paper presents a method using Lock-In Amplification (LIA) for bearing fault detection to overcome the limitations of signal-to-noise ratio (SNR) and enable specific detection. LIA is capable of extracting small signals from noise and detecting characteristic frequencies, even in the presence of external sources vibrating at the same frequencies as the motor of interest. Moreover, fractional harmonics LIA can detect characteristic frequencies from fault-free conditions, allowing for earlier failure detection and continuous monitoring.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Chemistry, Analytical
Eric Elzenheimer, Christin Bald, Erik Engelhardt, Johannes Hoffmann, Patrick Hayes, Johan Arbustini, Andreas Bahr, Eckhard Quandt, Michael Hoeft, Gerhard Schmidt
Summary: Dedicated research is being conducted on novel thin film magnetoelectric (ME) sensor concepts for medical applications. A quantitative evaluation of the sensor system and its output signals is necessary, along with a system consideration. The evaluation should be performed in reproducible measurement conditions, and an application-specific capacity (ASC) can be used as a figure of merit for a quantitative signal assessment. The approach can be applied to other magnetic sensors and applications.
Article
Neurosciences
Mevluet Yalaz, Nicholas Maling, Guenther Deuschl, Leon M. Juarez-Paz, Markus Butz, Alfons Schnitzler, Ann-Kristin Helmers, Michael Hoeft
Summary: This study presents an improved radiation-free method for detecting the position and orientation of directional deep brain stimulation (DBS) electrodes using magnetic detection. By using magnetoencephalography (MEG) measurements and model fitting, the position and orientation of the electrodes can be accurately determined. The accuracy of localization and orientation detection depends on the number of measurements and electrode configurations.
Article
Nanoscience & Nanotechnology
Cai Mueller, Phillip Durdaut, Rasmus B. Hollaender, Anne Kittmann, Viktor Schell, Dirk Meyners, Michael Hoeft, Eckhard Quandt, Jeffrey McCord
Summary: This study revealed the complex behavior of horizontally polarized surface shear waves in magnetoelectric surface acoustic wave based magnetic field sensor devices using time-resolved magnetooptical microscopy, uncovering partial surface wave reflections, wave front dephasing, and secondary wave generation originating from structures and magnetic domain walls.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Sabrina M. Curtis, Marian Sielenkaemper, Gowtham Arivanandhan, Duygu Dengiz, Zixiong Li, Justin Jetter, Lisa Hanke, Lars Bumke, Eckhard Quandt, Stephan Wulfinghoff, Manfred Kohl
Summary: The martensitic phase transformation in Ti40.4Ni48Hf11.6 shape memory alloys is utilized for bi-directional actuation with TiNiHf/SiO2/Si composites. The shape memory properties of Ti40.4Ni48Hf11.6 films are influenced by film thickness and substrate material. Thin films as low as 220 nm deposited on SiO2 buffer layer show transformations above room temperature, while films on Si substrates are austenitic at room temperature and not suitable for actuation. The thermal fatigue characteristics of TiNiHf/SiO2/Si bimorphs are better than freestanding films, and bi-directional actuation results with PMMA/TiNiHf/Si trimorph composite are promising.
INTERNATIONAL JOURNAL OF SMART AND NANO MATERIALS
(2022)
Article
Instruments & Instrumentation
Martina Matusko, Ivan Ryger, Gwenhael Goavec-Merou, Jacques Millo, Clement Lacroute, Emile Carry, Jean-Michel Friedt, Marion Delehaye
Summary: This article discusses the use of an FPGA platform for local ultra-stable optical frequency distribution in a fiber network. A novel protocol is presented that simplifies the setup and enables the distribution of ultra-stable frequencies. The performances of the system are demonstrated, showing an instability below 10(-17) at 1 s at the receiver end.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Chemistry, Analytical
Phillip Durdaut, Michael Hoeft
Summary: Piezoelectric layers coupled to micromechanical resonators are used as sensors for detecting various physical quantities. The performance of piezoelectric resonators in amplitude mode and phase mode is analyzed, considering sensitivities, noise behavior, and limits of detection. Frequency-dependent limits of detection are derived, and it is found that phase mode generally has better detection limits and wider bandwidth compared to amplitude mode.
Article
Environmental Sciences
Jean-Michel Friedt, Eric Bernard, Madeleine Griselin
Summary: The evolution of snowpack during the melt season on an Arctic glacier is assessed using ground-based cameras, spaceborne imaging, and spaceborne RADAR. Repeated and systematic RADAR imaging by Sentinel-1 RADARs allows for all-weather monitoring of the snow-covered fraction and its water production potential. Comparisons between RADAR reflectivity and optical/multispectral imaging highlight the differences in observed quantities and their complementarity in understanding snow melt processes. The study reveals a temporal inertia between visible spring melting and snow metamorphism, with the snowpack starting to fade approximately 30 days in advance.
Article
Engineering, Mechanical
Gowtham Arivanandhan, Zixiong Li, Sabrina M. Curtis, Lisa Hanke, Eckhard Quandt, Manfred Kohl
Summary: We propose a novel design approach to optimize the power consumption of cantilever-based shape memory alloy (SMA)/Si bimorph microactuators. By utilizing finite element simulation, additional folded beams are designed in the perpendicular direction to homogenize the temperature distribution along the cantilevers. The temperature-homogenized SMA/Si microactuators exhibit a significant reduction in power consumption compared to the conventional double-beam cantilever design, up to 48%.
Article
Materials Science, Multidisciplinary
Sabrina M. Curtis, Jascha L. Gugat, Lars Bumke, Duygu Dengiz, Lena Seigner, Don Schmadel, Nathan S. Lazarus, Eckhard Quandt
Summary: This paper presents the first numerical and experimental studies of freestanding thin-film TiNiCuCo superelastic alloys for stretchable interconnects. The superelastic conductor with a serpentine geometry achieves significantly larger elastic elongations compared to copper. The superior mechanical advantages of TiNiCuCo combined with the high electronic conductivity of copper make it a promising material for improving conductors in stretchable and flexible electronics.
SHAPE MEMORY AND SUPERELASTICITY
(2023)
Article
Physics, Applied
C. Fluhr, B. Dubois, C. E. Calosso, F. Vernotte, E. Rubiola, V. Giordano
Summary: This Letter reports on the exceptional frequency stability performance of an autonomous cryogenic sapphire oscillator (CSO), with a flicker frequency noise floor below 2 x 10(-16) and a long-term Allan deviation limited by a random walk process of around 1 x 10(-18) root tau, near 1000 seconds. The implementation of advanced instrumentation and ultra-stable frequency references was necessary to achieve this level. This result demonstrates the technological soundness of the CSO technology and sets a competitive upper limit for the ultimate noise floor of cryogenic microwave resonators comparable to ultra-stable optical Fabry-Perot cavities.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Enrico Rubiola, Francois Vernotte
Summary: Phase noise and frequency (in)stability describe the fluctuation of stable periodic signals from different perspectives. Frequency spans a wide range of magnitudes, from 10(-4) in a mechanical watch to 10(-18) in atomic clocks. The frequency span of interest for phase noise is from mu Hz to GHz Fourier frequency, while the fluctuation time spans from sub-mu s to years integration time for variances. The development of a common language and tools suitable for this domain is challenging due to its ubiquity in science and technology.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Christophe Fluhr, Benoit Dubois, Guillaume Le Tetu, Valerie Soumann, Julien Paris, Enrico Rubiola, Vincent Giordano
Summary: The cryogenic sapphire oscillator (CSO) is a specialized machine that provides the lowest frequency fluctuations for a microwave reference signal. It is based on a sapphire monocrystal resonating at 10 GHz and cooled to approximately 6 K. After implementing 11 CSOs over the span of ten years, significant progress has been made in short-term stability, reducing power consumption, and ensuring reproducible frequency stability and overall performance. The CSO is now a semi-commercial product suitable for scientific applications requiring extreme frequency stability and reliable long-term unattended operation.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Engineering, Electrical & Electronic
Stefan Moench, Jana Marie Meyer, Agne Zukauskaite, Vadim Lebedev, Simon Fichtner, Jingxiang Su, Florian Niekiel, Thorsten Giese, Lars Thormaehlen, Eckhard Quandt, Fabian Lofink
Summary: This study uses a surface acoustic wave magnetic field sensor to measure and control the inductor current in a GaN-based dc-dc power converter. The sensor is based on thin films of aluminium scandium nitride and has both dc and bidirectional current measurement capabilities. It is operated electrically isolated above the current trace.
IEEE SENSORS LETTERS
(2022)
