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Memory-assisted quantum accelerometer with multi-bandwidth

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Photonics Research 2022年第4期10卷 1022-1030页

作者： Zhifei Yu Bo Fang Liqing Chen Keye Zhang Chun-Hua Yuan Weiping Zhang State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200062China Shanghai Research Center for Quantum Sciences Shanghai 201315China School of Physics and Astronomy Shanghai Jiao Tong Universityand Tsung-Dao Lee InstituteShanghai 200240China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

The accelerometer plays a crucial role in inertial *** performance of conventional accelerometers such as lasers is usually limited by the sensing elements and shot noise limitation(SNL).Here,we propose an advanced development of an accelerometer based on atom–light quantum correlation,which is composed of a cold atomic ensemble,light beams,and an atomic vapor *** cold atomic ensemble,prepared in a magneto-optical trap and free-falling in a vacuum chamber,interacts with light beams to generate atom–light quantum *** atomic vapor cell is used as both a memory element storing the correlated photons emitted from cold atoms and a bandwidth controller through the control of free evolution *** of using a conventional sensing element,the proposed accelerometer employs interference between quantum-correlated atoms and light to measure *** below SNL can be achieved due to atom–light quantum correlation,even in the presence of optical loss and atomic *** can be achieved at the ng∕√Hz level,based on evaluation via practical experimental *** present design has a number of significant advantages over conventional accelerometers such as SNL-broken sensitivity,broad bandwidth from a few hundred Hz to near MHz,and avoidance of the technical restrictions of conventional sensing elements.

关键词： quantum accelerometer atomic

A polymeric piezoelectric MEMS accelerometer with high sensitivity,low noise density,and an innovative manufacturing approach

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Microsystems & Nanoengineering 2023年第6期9卷 149-164页

作者： Chang Ge Edmond Cretu The Department of Electrical and Computer Engineering The University of British ColumbiaVancouverCanada

The piezoelectric coupling principle is widely used(along with capacitive coupling and piezoresistive coupling)for MEMS *** MEMS accelerometers are used primarily for vibration *** piezoelectric MEMS accelerometers offer the merits of heavy-metal-free structure material and simple microfabrication *** importantly,polymeric piezoelectric MEMS accelerometers may be the basis of novel applications,such as fully organic inertial sensing microsystems using polymer sensors and organic integrated *** paper presents a novel polymer piezoelectric MEMS accelerometer design using PVDF films.A simple and rapid microfabrication flow based on laser micromachining of thin films and 3D stereolithography was developed to fabricate three samples of this *** proof-of-concept experiments,the design achieved a sensitivity of 21.82 pC/g(equivalent open-circuit voltage sensitivity:126.32 mV/g),a 5%flat band of 58.5 Hz,and a noise density of 6.02µg/√***,this design rivals state-of-the-art PZT-based counterparts in charge sensitivity and noise density,and it surpasses the performance capabilities of several commercial MEMS ***,this design has a 10-times smaller device area and a 4-times larger flat band than previous state-of-the-art organic piezoelectric MEMS *** experimentally validated performance metrics demonstrate the promising application potential of the polymeric piezoelectric MEMS accelerometer design presented in this article.

关键词： piezoelectric accelerometer noise

Mode-localized accelerometer with ultrahigh sensitivity

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Science China(Information Sciences) 2022年第4期65卷 238-250页

作者： Hao KANG Bing RUAN Yongcun HAO Honglong CHANG Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University

The mode localization phenomenon is an effective technique to enhance sensor sensitivity,and some low noise floor mode-localized sensors,including accelerometers,mass sensors,and electrometers,have been successfully *** further improve the performance of the mode-localized accelerometer,we report a microelectromechanical system mode-localized accelerometer based on 4-degree of freedom （DoF） weakly coupled resonators （WCRs） with a stress-relief structure eliminating the thermal stress generated during the silicon-on-glass fabrication *** results show that compared with the state-of-the-art 3-DoF mode-localized accelerometer (4.40 g-1),the amplitude ratio-based sensitivity of the proposed accelerometer(119.36 V·g-1) is improved by 2612%.Moreover,the noise floor is 0.64μg·Hz-1/2from 0.01 to 3 Hz under the closed-loop *** the authors’best knowledge,this is the lowest measured noise floor for mode-localized accelerometers.

关键词： mode localization weakly coupled resonators accelerometer degree-of-freedom microe-lectromechanical system

High-Performance Single-Side Fabricated (111)-Silicon Dual-Cantilever accelerometer with Squeeze-Film Air Damping Modulation

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Journal of Shanghai Jiaotong university(Science) 2023年第2期28卷 197-206页

作者：焦鼎倪藻王家畴李昕欣 State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China School of Microelectronics University of Chinese Academy of SciencesBeijing 100049China

This study proposes a novel design and micromachining process for a dual-cantilever *** and curved-surface structures are integrated into the sensing structure to modulate the squeeze-film damping,thus effectively optimizing the response frequency *** to the high stress concentration on the dual-cantilever integrated with a fully sensitive piezoresistive Wheatstone bridge,a high sensitivity to acceleration is *** addition,the dual-cantilever accelerometer is fabricated using a specifically developed low-cost and high-yield(111)-silicon single-side bulk-micromachining *** test results show that the proposed dualcantilever accelerometer exhibits a sensitivity of 0.086—0.088 mV/g/3.3 V and a nonlinearity of±(0.09%—0.23%)FS(full-scale).Based on dynamic characterization,an adequate frequency bandwidth of 2.64 kHz is ***,a resonant frequency of 4.388 kHz is measured,and a low quality factor(Q)of 7.62 is obtained,which agrees well with the design for air-damping *** achieved high performance renders the proposed dual-cantilever accelerometer promising in applications such as automotive and consumer electronics.

关键词： accelerometer cantilever piezoresistance micromachining squeeze-film damping

Step volume and intensity in older adults:Commentary on "Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults:A prospective cohort study"

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Journal of Sport and Health Science 2022年第5期11卷 548-549页

作者： Cayla McAvoy Catrine Tudor-Locke College of Health and Human Services University of North Carolina at CharlotteCharlotteNC 28223USA

In 2021,Manas et al.1 used data from the Toledo Study for Healthy Aging and reported that high accelerometer-derived step volume and(what they labeled)intensity were significantly associated with lower hospitalization(average followup=3.1 years)and all-cause mortality(average followup=5.7 years)in 768 older adults(average age=78.8±4.9 years,mean±SD).Step volume(expressed as steps/day)was averaged across all compliant days(i.e.,those with>8 h/day of valid wear time).For their purposes,the authors defined intensity as the total step volume divided by the total valid minutes of accelerometer wear time.

关键词： wear accelerometer steps

Response to McAvoy and Tudor-Locke on their commentary on our manuscript:“Association of accelerometer-derived step volume and intensity with hospitalizations and mortality in older adults:A prospective cohort study”

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Journal of Sport and Health Science 2022年第6期11卷 639-640页

作者： Asier Mañas Borja del Pozo Cruz Ulf Ekelund JoséLosa Reyna Irene Rodríguez Gómez JoséAntonio Carnicero Carreño Leocadio Rodríguez Mañas Francisco J.García García Ignacio Ara GENUD Toledo Research Group University of Castilla-La ManchaToledo 45071Spain CIBER of Frailty and Healthy Aging(CIBERFES) Instituto de Salud Carlos IIIMadrid 28029Spain Center UCM-ISCIII for Human Evolution and Behavior Madrid 28029Spain Faculty of Education Complutense University of MadridMadrid 28040Spain Biomedical Research and Innovation Institute of Cadiz(INiBICA)Research Unit Puerto Real University HospitalUniversity of CadizCadiz 11009Spain Department of Physical Education Faculty of Education SciencesUniversity of CadizCadiz 11009Spain Department of Sports Medicine Norwegian School of Sport SciencesOslo 0806Norway Department of Chronic Diseases and Ageing Norwegian Institute of Public HealthOslo 0473Norway Geriatric Department Hospital Universitario de GetafeGetafe 28905Spain Geriatric Department Hospital Virgen del ValleToledo 45071Spain

Dear Editor,We have read with interest the commentary by McAvoy and Tudor-Locke on our article entitled "Association of accelerometer-derived step volume and intensity with ho spitalizations and mortality in older adults:A prospective cohort study". The authors expressed some concerns about our methodology used to define accelerometer-derived step intensity and the analytical approach applied in our study.

关键词： accelerometer prospective mortality

Micro 3D printing of a functional MEMS accelerometer

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Microsystems & Nanoengineering 2022年第5期8卷 69-79页

作者： Simone Pagliano David E.Marschner Damien Maillard Nils Ehrmann Göran Stemme Stefan Braun Luis Guillermo Villanueva Frank Niklaus KTH Royal Institute of Technology Division of Micro and NanosystemsMalvinas väg 10StockholmSweden École Polytechnique Fédérale de Lausanne(EPFL) Advanced NEMS LaboratoryInstitute of Mechanical Engineering1015 LausanneSwitzerland Hochschule Kaiserslautern University of Applied SciencesInformatik und MikrosystemtechnikCampus ZweibrückenGermany

Microelectromechanical system(MEMS)devices,such as accelerometers,are widely used across industries,including the automotive,consumer electronics,and medical *** are efficiently produced at very high volumes using large-scale semiconductor manufacturing ***,these techniques are not viable for the costefficient manufacturing of specialized MEMS devices at low-and medium-scale ***,applications that require custom-designed MEMS devices for markets with low-and medium-scale volumes of below 5000–10,000 components per year are extremely difficult to address *** 3D printing of MEMS devices could enable the efficient realization and production of MEMS devices at these low-and medium-scale ***,current micro-3D printing technologies have limited capabilities for printing functional ***,we demonstrate a functional 3D-printed MEMS accelerometer using 3D printing by two-photon polymerization in combination with the deposition of a strain gauge transducer by metal *** characterized the responsivity,resonance frequency,and stability over time of the MEMS *** results demonstrate that the 3D printing of functional MEMS is a viable approach that could enable the efficient realization of a variety of custom-designed MEMS devices,addressing new application areas that are difficult or impossible to address using conventional MEMS manufacturing.

关键词： printing accelerometer functional

An improved quaternion Gauss–Newton algorithm for attitude determination using magnetometer and accelerometer

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Chinese Journal of Aeronautics 2014年第4期27卷 986-993页

作者： Liu Fei Li Jie Wang Haifu Liu Chang School of Mechatronical Engineering Beijing Institute of Technology

For the vector attitude determination, the traditional optimal algorithms which are based on quaternion estimator（QUEST） measurement noise model are complicated for just two observations. In our application, the magnetometer and accelerometer are not two comparable kinds of sensors and both are not small field-of-view sensors as well. So in this paper a new unit measurement model is derived. According to the Wahba problem, the optimal weights for each measurement are obtained by the error variance researches. Then an improved quaternion Gauss–Newton method is presented and adopted to acquire attitude. Eventually, simulation results and experimental validation employed to test the proposed method demonstrate the usefulness of the improved algorithm.

关键词： accelerometer Attitude determination Gauss-Newton algorithm Magnetometer Measurements

Design and noise analysis of a sigma-delta capacitive micromachined accelerometer

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Journal of Semiconductors 2010年第5期31卷 96-101页

作者：刘云涛刘晓为陈伟平吴群 MEMS Center Harbin Institute of Technology College of Information and Communication Engineering Harbin Engineering University

A single-loop fourth-order sigma-delta（ΣΔ） interface circuit for a closed-loop micromachined accelerometer is *** additional electronic integrators are cascaded with the micromachined sensing element to form a fourth-order loop *** three main noise sources affecting the overall system resolution of aΣΔaccelerometer, mechanical noise,electronic noise and quantization noise,are analyzed in *** mathematical formulas for electronic and quantization noise are *** ASIC is fabricated in a 0.5μm two-metal two-poly n-well CMOS *** test results indicate that the mechanical noise and electronic noise are 1μg/（Hz）^（1/2） and 8μV/（Hz）^（1/2） respectively,and the theoretical models of electronic and quantization noise agree well with the test and simulation results.

关键词： noise analysis sigma-delta micromachined accelerometer ASIC